Hillary Clinton and Bernie Sanders are both left of center, but there is visible ideological distance between them regarding the scope of government. The distance between John Kasich and Ted Cruz is harder to spot. All the remaining Republican candidates want to cut taxes for the wealthy, defund Planned Parenthood, and resist minimum wage hikes. They even all agree on building a wall on the border with Mexico.

So why is the Republican Party the one that’s on the verge of cracking up?

A mere 51 percent of Republican voters would be “satisfied” if the current frontrunner Donald Trump is the nominee, according to a recent ABC/Washington Post poll. The numbers for Marco Rubio and Cruz are better, but not stellar: 62 percent and 65 percent, respectively. The Democrats are in stronger shape: Both Clinton and Sanders clear 70 percent.

With the Grand Old Party increasingly divided along Trump and anti-Trump lines, one camp will likely walk away from the Republican National Convention in July embittered. Either the #NeverTrump faction will follow through on its pledge to abandon the party nominee, or Trump’s loyal fans will rage at how the Republican establishment stole the nomination from their insurgent leader and take a pledge of their own.

The last time the party suffered a convention walkout was in 1912, when Teddy Roosevelt and his delegates walked across the street to launch the Progressive Party. Then, the divide between Roosevelt and President William Taft was about the ideological role of government, a hard gap to bridge.