(CNN) Donald Trump descended the famous escalator in Trump Tower one year ago Thursday to launch a presidential campaign that seemed so outrageous, provocative and unconventional that it was dismissed as reality television.

A year later, Trump is the presumptive Republican nominee. His showman style -- with its brass-knuckled tactics, defiance of decorum and itchy-Twitter-finger approach -- has created a new brand of politics that is entirely his own.

Now he is testing the limits of his persona during the general election campaign. Republican leaders are distancing themselves from their nominee and his controversial remarks -- and he is threatening to go it alone without their help.

Never have the lines between news and entertainment been blurred as much as they have in this presidential cycle. Trump has driven breathless, minute-by-minute press coverage injected with all the drama of a telenovela. Even amid the carnage and mourning in the aftermath of the deadliest mass shooting in U.S. history, this week was no exception.

Trump's wild ride to take over the GOP

Trump's wild ride to take over the GOP 03:25

Trump's wild ride to take over the GOP

Trump used teleprompters and a statesman-like setting to address the nation, but the speech was every bit as outrageous, must-see-TV as Hillary Clinton's was predictable. Some Republicans watched with amazement as Trump used the mass tragedy to cast suspicion on President Barack Obama, renew his call for a Muslim travel ban, and advance the eyebrow-raising proposal that the United States should seal its borders to all immigrants from areas of the world where there is a proven history of terrorism against the U.S. and its allies.

With a mind-bending twist that perhaps only Trump could pull off, a candidate who opposes gay marriage and has spent the past year appealing to social conservatives justified his proposed ban by stating it was necessary to protect the LGBT community, which was targeted in Sunday's shooting in Orlando.

"We are taking in thousands of people into our country. We have no idea where they come from. We have no idea who the hell they are," Trump said on the campaign trail on Wednesday. "We aren't vigilant and we aren't smart. And we have to go and we have to maybe check, respectfully, the mosques."

Trump's rhetoric this week, which was couched in a rejection of political correctness, elicited outrage from Obama.

"Where does this stop?" he asked.

House Speaker Paul Ryan, who is backing Trump, was forced to again denounce Trump's call for a ban on travel by Muslims.

The show goes on

But the Trump show went on. He dismissed the rejection of his remarks by the President as though the two were engaged in a personal quarrel. The real estate mogul reacted to the obvious discomfort among Republicans with a vague threat of parting ways with the party.

Reprimanding Republican leaders as needing to get "tougher" or "be quiet." he said "We have to have our Republicans either stick together or let me just do it by myself. I'm going to do very well."

Though Trump's unfavorability ratings have risen to their highest level -- 70% -- in a new Washington Post/ABC poll, Trump suggested Wednesday that his standing would improve after the "horrendous, horrendous attack."

"I tell you people are tired, they want to have strength, they want to have intelligence," he said during a speech in Atlanta.

Clinton and Trump, ever-present figures on television and in popular culture for decades, are the biggest stars to face off in a general election in generations. Their responses to the tragedy in Orlando illustrate the vastly different ways they intend to harness that star power and will serve as the strongest test yet of whether merging celebrity and politics can win the presidency.

Clinton, with her reserved, risk-averse, intellectual image, is betting the American people will ultimately choose steady over unpredictable—even though voters have signaled a vast appetite for change and a new kind of politics.

Once again this week, she called Trump "tempermentally unfit" for the presidency: "It was one thing when he was a reality TV personality -- you know, raising his arms and yelling, 'You're fired," Clinton said in Pittsburgh. "It is another thing altogether when he's the Republican Party's presumptive nominee for President."

At the same time, Trump's formula faces new scrutiny as he tries to appeal to a far more diverse general election audience in the wake of domestic terror attack.

From his hail fire of tweets assigning blame after the Orlando shooting to his attention-grabbing antics like revoking the credentials of the Washington Post Monday, he is testing the limits of whether that broader swath of the electorate will embrace his showman's persona at a time when the nation is gripped by fear and anxiety about terrorism.

As officials were still identifying bodies from Orlando's Pulse nightclub Sunday, Trump first tweeted that he was praying for the victims. He then rebuked past criticism of his campaign with breathtaking bravado: "Appreciate the congrats for being right on radical Islamic terrorism, I don't want congrats, I want toughness & vigilance. We must be smart!"

He then successfully stirred up a daylong controversy over whether Obama and Clinton would use the words "radical Islamic terrorism" and blamed "weak and ineffective" leadership for the ban.

His vague comments seeming to link Obama to the Orlando shooting in a Fox interview Monday sparked a new firestorm.

By Monday evening, when Clinton's campaign chairman was offered his critique of Trump's speech as a "rambling remarks" that offered nothing that "came close to resembling a real strategy for fighting terrorists," Trump had already moved on to his next line of attack against Clinton -- via Twitter.

Noting that Clinton called on the Saudis, the Qataris and the Kuwaitis to "stop their citizens from funding extremist organizations," Trump accused her of hypocrisy by noting that the Clinton Foundation has taken millions from the Kingdom of Saudi Arabia.

"Crooked Hillary says we must call on Saudi Arabia and other countries to stop funding hate. I am calling on her to immediately return the $25 million plus she got from them for the Clinton Foundation!" Trump wrote on Twitter and Facebook.

Similar challenges

For all that's different about their clashing styles, in some ways Trump and Clinton face some of the same challenges as they try to persuade voters this fall.

They are two of the most famous people in the world with near universal name recognition. They also have the highest unfavorable ratings of any candidates who have ever run for president.

Trump has scoffed at the notion that he would make some kind of general election pivot and begin behaving like the decorous GOP nominee of elections past.

Clinton, in turn, has made it clear that she will try to run as a statesman -- brushing off Trump's innuendo, ignoring his provocations about her personal life, and framing her general election campaign as a point-by-point takedown of Trump's knowledge, temperament and fitness to serve as commander-in-chief.

Photos: Donald Trump's rise Photos: Donald Trump's rise President-elect Donald Trump has been in the spotlight for years. From developing real estate and producing and starring in TV shows, he became a celebrity long before winning the White House. Hide Caption 1 of 37 Photos: Donald Trump's rise Trump at age 4. He was born in 1946 to Fred and Mary Trump in New York City. His father was a real estate developer. Hide Caption 2 of 37 Photos: Donald Trump's rise Trump, left, in a family photo. He was the second-youngest of five children. Hide Caption 3 of 37 Photos: Donald Trump's rise Trump, center, stands at attention during his senior year at the New York Military Academy in 1964. Hide Caption 4 of 37 Photos: Donald Trump's rise Trump, center, wears a baseball uniform at the New York Military Academy in 1964. After he graduated from the boarding school, he went to college. He started at Fordham University before transferring and later graduating from the Wharton School, the University of Pennsylvania's business school. Hide Caption 5 of 37 Photos: Donald Trump's rise Trump stands with Alfred Eisenpreis, New York's economic development administrator, in 1976 while they look at a sketch of a new 1,400-room renovation project of the Commodore Hotel. After graduating college in 1968, Trump worked with his father on developments in Queens and Brooklyn before purchasing or building multiple properties in New York and Atlantic City, New Jersey. Those properties included Trump Tower in New York and Trump Plaza and multiple casinos in Atlantic City. Hide Caption 6 of 37 Photos: Donald Trump's rise Trump attends an event to mark the start of construction of the New York Convention Center in 1979. Hide Caption 7 of 37 Photos: Donald Trump's rise Trump wears a hard hat at the Trump Tower construction site in New York in 1980. Hide Caption 8 of 37 Photos: Donald Trump's rise Trump was married to Ivana Zelnicek Trump from 1977 to 1990, when they divorced. They had three children together: Donald Jr., Ivanka and Eric. Hide Caption 9 of 37 Photos: Donald Trump's rise The Trump family, circa 1986. Hide Caption 10 of 37 Photos: Donald Trump's rise Trump uses his personal helicopter to get around New York in 1987. Hide Caption 11 of 37 Photos: Donald Trump's rise Trump stands in the atrium of the Trump Tower. Hide Caption 12 of 37 Photos: Donald Trump's rise Trump attends the opening of his new Atlantic City casino, the Taj Mahal, in 1989. Hide Caption 13 of 37 Photos: Donald Trump's rise Trump signs his second book, "Trump: Surviving at the Top," in 1990. Trump has published at least 16 other books, including "The Art of the Deal" and "The America We Deserve." Hide Caption 14 of 37 Photos: Donald Trump's rise Trump and singer Michael Jackson pose for a photo before traveling to visit Ryan White, a young child with AIDS, in 1990. Hide Caption 15 of 37 Photos: Donald Trump's rise Trump dips his second wife, Marla Maples, after the couple married in a private ceremony in New York in December 1993. The couple divorced in 1999 and had one daughter together, Tiffany. Hide Caption 16 of 37 Photos: Donald Trump's rise Trump putts a golf ball in his New York office in 1998. Hide Caption 17 of 37 Photos: Donald Trump's rise An advertisement for the television show "The Apprentice" hangs at Trump Tower in 2004. The show launched in January of that year. In January 2008, the show returned as "Celebrity Apprentice." Hide Caption 18 of 37 Photos: Donald Trump's rise A 12-inch talking Trump doll is on display at a toy store in New York in September 2004. Hide Caption 19 of 37 Photos: Donald Trump's rise Trump attends a news conference in 2005 that announced the establishment of Trump University. From 2005 until it closed in 2010, Trump University had about 10,000 people sign up for a program that promised success in real estate. Three separate lawsuits -- two class-action suits filed in California and one filed by New York's attorney general -- argued that the program was mired in fraud and deception. Trump's camp rejected the suits' claims as "baseless." And Trump has charged that the New York case against him is politically motivated. Hide Caption 20 of 37 Photos: Donald Trump's rise Trump attends the U.S. Open tennis tournament with his third wife, Melania Knauss-Trump, and their son, Barron, in 2006. Trump and Knauss married in 2005. Hide Caption 21 of 37 Photos: Donald Trump's rise Trump wrestles with "Stone Cold" Steve Austin at WrestleMania in 2007. Trump has close ties with the WWE and its CEO, Vince McMahon. Hide Caption 22 of 37 Photos: Donald Trump's rise For "The Apprentice," Trump was honored with a star on the Hollywood Walk of Fame in January 2007. Hide Caption 23 of 37 Photos: Donald Trump's rise Trump appears on the set of "The Celebrity Apprentice" with two of his children -- Donald Jr. and Ivanka -- in 2009. Hide Caption 24 of 37 Photos: Donald Trump's rise Trump poses with Miss Universe contestants in 2011. Trump had been executive producer of the Miss Universe, Miss USA and Miss Teen USA pageants since 1996. Hide Caption 25 of 37 Photos: Donald Trump's rise In 2012, Trump announces his endorsement of Republican presidential candidate Mitt Romney. Hide Caption 26 of 37 Photos: Donald Trump's rise Trump speaks in Sarasota, Florida, after accepting the Statesman of the Year Award at the Sarasota GOP dinner in August 2012. It was shortly before the Republican National Convention in nearby Tampa. Hide Caption 27 of 37 Photos: Donald Trump's rise Trump appears on stage with singer Nick Jonas and television personality Giuliana Rancic during the 2013 Miss USA pageant. Hide Caption 28 of 37 Photos: Donald Trump's rise In June 2015, during a speech from Trump Tower, Trump announced that he was running for President. He said he would give up "The Apprentice" to run. Hide Caption 29 of 37 Photos: Donald Trump's rise Trump -- flanked by U.S. Sens. Marco Rubio, left, and Ted Cruz -- speaks during a CNN debate in Miami on March 10. Trump dominated the GOP primaries and emerged as the presumptive nominee in May. Hide Caption 30 of 37 Photos: Donald Trump's rise The Trump family poses for a photo in New York in April. Hide Caption 31 of 37 Photos: Donald Trump's rise Trump speaks during a campaign event in Evansville, Indiana, on April 28. After Trump won the Indiana primary, his last two competitors dropped out of the GOP race. Hide Caption 32 of 37 Photos: Donald Trump's rise Trump delivers a speech at the Republican National Convention in July, accepting the party's nomination for President. "I have had a truly great life in business," he said. "But now, my sole and exclusive mission is to go to work for our country -- to go to work for you. It's time to deliver a victory for the American people." Hide Caption 33 of 37 Photos: Donald Trump's rise Trump faces Democratic nominee Hillary Clinton in the first presidential debate, which took place in Hempstead, New York, in September. Hide Caption 34 of 37 Photos: Donald Trump's rise Trump apologizes in a video, posted to his Twitter account in October, for vulgar and sexually aggressive remarks he made a decade ago regarding women. "I said it, I was wrong and I apologize," Trump said, referring to lewd comments he made during a previously unaired taping of "Access Hollywood." Multiple Republican leaders rescinded their endorsements of Trump after the footage was released. Hide Caption 35 of 37 Photos: Donald Trump's rise Trump walks on stage with his family after he was declared the election winner on November 9. "Ours was not a campaign, but rather, an incredible and great movement," he told his supporters in New York. Hide Caption 36 of 37 Photos: Donald Trump's rise Trump is joined by his family as he is sworn in as President on January 20. Hide Caption 37 of 37

The former secretary of state is showing a greater willingness to take on Trump more directly in pointed speeches and pithy tweets. But she has yet to prove that she can be nimble and effective in the new, furiously-paced political arena that Trump has created, and controlled for the past ten months.

"His use of Twitter as a communication medium to bring conflict to his opponents, and have that conflict covered by the media in the way that ESPN covers sports is transformational in politics," said Steve Schmidt, a Republican strategist who ran John McCain's campaign in 2008.

With Trump's skeletal campaign staff and paltry spending on advertising, he has challenged the notion that a presidential campaign needs a massive infrastructure with hundreds of staff members and well-heeled strategists (though that may come back to haunt him as Clinton's ground game rolls into gear).

Trump has also single-handedly redefined the bounds of what a candidate can say or do.

"The culture around politics and discussion on the comment threads and the blogs has been disgusting for a long time," Schmidt said. "But candidates conducted themselves with a level of decorum and a sense of guard rails of what could be said. He's shattered that."

Beyond the vitriol and shocking statements, UCLA political science professor Lynn Vavreck, argues that the other revolutionary aspect of his campaign, is the fact that he is running his political operation the same way he would run his business with "a set of tactics, instead of a set of long term strategies."

In that sense Trump has taken political marketing and branding to a new level. It isn't just his refusal to back down when challenged over controversial statements or proposals -- like the Muslim ban that he doubled down on Monday -- but that he seems intent on following the mantra that he must repeat the same message over and over again, louder and louder. Everything he does is the best, the most amazing, and now he would extend his golden touch to "Make America Great Again."

"It's the idea of business marketing, that if you can just convince the consumer that your product really is better, you're winning," said Vavreck, who co-authored "The Gamble: Choice and Chance in the 2012 Presidential Election."

Irony

She noted the irony of how much the political landscape has changed since 1952, when then presidential candidate Adlai Stevenson refused to appear in political ads, because he said American people would be shocked "by such contempt for their intelligence" because the race for a White House wasn't "Ivory Soap versus Palmolive."

By contrast, Vavreck said, "Trump has turned himself into a bar of soap. He's brought this business marketing model to the presidential campaign in a way that nobody's done before."

It is far too early to predict whether any downballot candidates will try to replicate Trump's style -- or if any of them can command the stage as he has.

But many are watching closely to see how Clinton will adapt, and whether Trump's style will wear on voters over time -- particularly on those Republicans who were cool to him during the primary process.

Veteran Democratic Strategist Bill Carrick noted that Trump has a challenging task ahead -- particularly as the spotlight winnows to just two candidates and voters draw closer to decision time.

"There was a huge difference between him and the 17 other Republicans who ran—he commanded incredible attention because he was more interesting as a personality, more interesting as an ideological outlier in the Republican Party, more interesting as this bombastic bully," said Carrick. "In the general election, it's a one-on-one contest. He's got to get more than 30% of the vote; and he's got to give the group of voters who have not participated in the primary some confidence that he's capable of being president."

As he faced the new test of his candidacy for the White House this week in the wake of a national tragedy, Trump reflected on the past year.

"I came down those escalators. And who knew this was going to happen," Trump said. "It's been an amazing journey."