Senate Democrats took the chamber floor to filibuster for stricter gun control legislation Wednesday, just days after a gunman opened fire at a gay nightclub in Orlando, killing 49 people and injuring dozens of others.

Sen. Chris Murphy, D-Connecticut, began stalling work on a spending bill Wednesday morning, hoping to push the Senate into considering two gun control measures that would require universal background checks for all firearm purchases and would bar anyone on a no-fly terror watch list from buying guns. By late Wednesday night, he was still going.

"This isn't new to me, but I'm at my wit's end. I've had enough," said Murphy, who has been a vocal gun control advocate since the Sandy Hook massacre shook Newtown, Connecticut in 2012. "I've had enough of the ongoing slaughter of innocents, and I've had enough of inaction in this body."

"I'm going to remain on this floor until we get some signal -- some sign -- that we can come together on these two measures, that we can get a path forward on addressing this epidemic in a meaningful, bipartisan way," he added.

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On Twitter, Murphy said he would continue speaking "for as long as I can."

I am prepared to stand on the Senate floor and talk about the need to prevent gun violence for as long as I can. I've had #Enough — Chris Murphy (@ChrisMurphyCT) June 15, 2016

Murphy, who began speaking on the floor around 11:21 a.m. Wednesday, swapped out with other Democratic senators during the extended debate. Sens. Richard Blumenthal, D-Connecticut, Cory Booker, D-New Jersey, and Dick Durbin, D-Illinois, all joined in with Murphy's legislative agenda.

By Wednesday night, eight hours in, another senator asked how Murphy was feeling; he replied that rehab from a back injury was younger helped him prepare for the long hours on the Senate floor.

At one point in the night, Murphy's two sons watched from above in the galleries. Apart from several of his Democratic Senate colleagues, the chamber remained largely empty during Murphy's filibuster.

Other legislators expressed their support of the filibuster, including representatives from Connecticut.

Happening now: @RepJoeCourtney and I on our way to the Senate to support @ChrisMurphyCT in his gun safety filibuster pic.twitter.com/xsgDO0mYKL — Jim Himes (@jahimes) June 15, 2016

And Democratic presidential candidate and Vermont Sen. Bernie Sanders also tweeted out that he stood with Murphy's "common sense gun safety" demands.

I stand with @ChrisMurphyCT to demand common sense gun safety. We can't allow guns to fall into the hands of people who shouldn't have them. — Bernie Sanders (@SenSanders) June 15, 2016

The floor filibuster comes just as Donald Trump, the presumptive GOP nominee, announced a meeting with the National Rifle Association (NRA) to discuss the possibility of no-fly, no-buy legislation.

Trump, who said back in November that he would "absolutely" support preventing those on no-fly lists from obtaining firearms, has found an unlikely ally in Hillary Clinton, the presumptive Democratic nominee for president.

In a Wednesday interview with the Huffington Post, Clinton welcomed Trump to the gun control efforts.

"The NRA and the other gun lobby members should be moving rapidly to work with Congress on this legislation," she said. "I know members of Congress, hopefully on both sides of the aisle, are beginning to look to see if they can pass this. And I fully support it."

Other Democratic lawmakers have become increasingly aggressive on gun control policies in light of the violence in Orlando over the weekend.

Earlier this week, legislators on the House floor shouted down Speaker Paul Ryan, R-Wisconsin, after he held a moment of silence for the Orlando shooting victims.

"Where's the bill?" Democrats yelled out, calling on the House to address gun control legislation.

Republicans, however, have remained steadfast in their opposition to stricter gun control legislation, despite recent polling that suggests stricter laws are a popular policy position among most Americans.

Ryan's office, for instance, has pointed out in the past that even FBI Director James Comey has warned against using terror watch lists to flag gun buyers because it could tip off potential suspects.

"It's a little bit challenging for us because 'known' or 'suspected' means it hasn't been adjudicated in every case that somebody is a terrorist," Comey said in March last year. "It's somebody we're investigating, so we don't want to, obviously, blow our investigation."Speaking with reporters Wednesday evening, Sen. Dianne Feinstein, D-California, said she did not know that she and Sen. John Cornyn, R-Texas, would be able to come to a compromise on language about the terror watch lists.

"I don't think that is going to work out," she said. "I'm still working with others."

CBS News' Steven Portnoy contributed to this report.