Imagine if they did? Trump’s core voters may loathe the GOP establishment. For them, hearing that a prominent Republican was voting for Clinton would just intensify their disdain. But Trump’s gains over the last week have not come from such people. They’ve come largely from voters who generally vote Republican but dislike Trump. As Mike Pence declared triumphantly this week, “Republicans across the country are coming home.” If these voters heard prominent Republicans explaining why Hillary is an acceptable choice, it might influence their vote. It would particularly influence Republicans who are supporting Gary Johnson or Evan McMullin.

Why won’t pro-Clinton Republicans do that? Because they fear the political blowback. Given Trump’s grassroots support, it’s dangerous enough for a GOP politician or pundit to oppose him. In a party where merely raising the debt ceiling gets you labeled a RINO, publicly supporting Clinton could be career threatening.

Then again, the Republicans who oppose Trump cherish the Constitution. And they know that Trump—even if he shares their views on immigration and tax cuts—threatens it in ways that Clinton does not. He threatens it in ways that no modern presidential candidate ever has. He’s the only major party presidential nominee in modern history who could plausibly turn the United States into an illiberal democracy.

One day, after they’ve left politics, and after Trump has receded into historical infamy, the Republicans who next week vote for Hillary Clinton will proudly tell their grandchildren that they did. But it will be too late. Today, according to FiveThirtyEight, Trump has an almost one-in-three chance of becoming America’s next president. By hiding their support for Clinton out of fear, some of America’s most prominent Republicans are making his election more likely. If he wins, that cowardice will haunt them for the rest of their lives.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.