In the end, the strongest argument for a Trump vote has always been this:

WILLIAM MCGURN WAll Street Journal

Oct. 17, 2016 7:12 p.m. ET

1538 COMMENTS

Three weeks out from Election Day, the Never Trump argument has been neatly summed up by Bill Maher. Not only is Donald Trump coarse and boorish, anyone who supports the man is as revolting as he is.

On his show last month, Mr. Maher put it this way to Trump campaign manager Kellyanne Conway: “You are enabling pure evil.” The HBO comedian went on to amuse himself by adding that “Hillary was right when she called a lot of his supporters deplorable.”

Mr. Maher might have added that it is also a well-worn Democratic trope. After all, wasn’t it Barack Obama who described small-town Americans as bitterly clinging to guns and religion and disliking anyone who is different? As for Hillary Clinton, in her deplorables crack she dismissed half of Mr. Trump’s followers as “racist, sexist, homophobic.” Less well noted (but more telling), she also declared them “irredeemable.”

This is an old argument for the left. But Republicans are now hearing it from the right as well. Which puts conservative Never Trumpers in a curious position vis-à-vis government of, by and for the people: Are the tens of millions of Americans who will pull the lever for Trump come November evil too, or just invincibly stupid?

Give the Never Trumpers their due: Most do not shy away from the implication that anyone who would vote for Mr. Trump is as low and base as he is. Their problem is that the argument doesn’t seem to be having much traction with Republican voters. A Rasmussenpoll released Monday found that while Mrs. Clinton enjoys the support of 78% of Democrats, Mr. Trump is supported by 74% of Republicans. Other polls show that even after all his fumbles and embarrassments, the vast majority of Republicans do not want Mr. Trump to drop out.

One reason may be that the argument about morally corrupt GOP voters is not really an argument. More precisely, it’s an argument Republicans typically hear from the left. Instead of weighing the prosaic facts—i.e., the practical ramifications of having Mrs. Clinton sitting in the Oval Office versus Mr. Trump—how much easier it is to try to end all discussion by pronouncing the GOP nominee repellent.

Trump supporters get this. Probably few were surprised by the “Access Hollywood” tape that showed Mr. Trump in full Bill Clinton mode. They support him in spite of it.

They support him because they fear political correctness is making vital discussions about the country impossible—and conclude that any candidate who’s going to take this on is not going to be Miss Manners. They support him because they know what they will get if Mrs. Clinton wins, as now looks likely.

They support him because they get the contempt dripping from Mr. Obama and Mrs. Clinton whenever the subject is the things they cherish: faith, patriotism, the decency of ordinary citizens, and so on. Above all, they support him because they also get that the elite contempt for Donald Trump is a proxy contempt for them.

Still, each new day brings new accusations and analogies. Like college sophomores ransacking history for the most extreme metaphors, no pejorative is too fantastic. Trump is Hitler! Trump is Mussolini! Trump is Nietzsche! Even George Will just likened the GOP convention to a “mini-Nuremberg.”

Ironically, the cheapest moralizing has been reserved for those trying to make the best of a bad situation. Thus Trump running mate Mike Pence finds himself accused of moral turpitude for working to keep the Republican Party from coming apart and giving voters some hope for a conservative agenda if Mr. Trump were to win.

Ditto for House Speaker Paul Ryan, excoriated by the Trumpers for his efforts to preserve the GOP’s House majority and by Never Trumpers for refusing to un-endorse the Republican nominee. Mr. Ryan understands that losing the Congress would give President Hillary Clinton two years to push through the progressive wish list, not to mention putting a liberal majority on the Supreme Court, preserving ObamaCare and maintaining the travesty that is the nuclear deal with Iran. Having watched what the 2010 GOP House takeover did to the Obama agenda, she would no doubt take full advantage of the time she has to act.

In the end, the strongest argument for a Trump vote has always been this: The alternative is a president who lies, whose public life has been a series of scandals from cattle futures to the destruction of documents under subpoena, who would be a third term for disastrous Obama policies at home and abroad, and who has never taken a position that wasn’t done from naked political expediency—from supporting the Iraq war in 2002 or opposing it later to invoking Abraham Lincoln to justify saying one thing in public and another in private.

Meanwhile, the Never Trump movement’s contribution has been to give us a word for all those who have weighed this evidence and have found the argument against a Clinton presidency persuasive: evil.

Write to mcgurn@wsj.com.