By Paul Krugman – The New York Times.

Donald Trump said some more disgusting things over the weekend. If this surprises you, you haven’t been paying attention. Also, don’t be surprised if a majority of Republicans approve of his attack on the parents of a dead war hero. After all, a YouGov survey found that 61 percent of Republicans support his call for Russian hacking of Hillary Clinton.

But this isn’t a column about Mr. Trump and the people who are O.K. with anything he says or does. It is, instead, about Republicans — probably a minority within the party, but a substantial one — who aren’t like that. These are people who aren’t racists, respect patriots even if they’re Muslim, believe that America should honor its international commitments, and in general sound like normal members of a normal political party.

Yet the great majority of these not-crazy Republicans are still supporting Mr. Trump for president. And we have a right to ask why.

True, a Clinton victory would mean a continuation of the center-left governance we’ve had under Barack Obama, which would be a big disappointment for those who want a turn to the right. And many people have convinced themselves that ideology aside, Mrs. Clinton would be a bad president. Obviously I disagree on the ideology, and while we won’t know about a Clinton presidency until or unless it happens, I find much to admire in the real Hillary, who is nothing like the caricature. But never mind: even if you’re a conservative who really dislikes the Democratic candidate, how can you justify choosing Donald Trump?

Put it this way: Is there any reason to believe that a Clinton victory would lead to irretrievable disaster? Because that’s the question you should be asking yourself.

Start with the least important issue (even if it is my specialty), economics. If you’re a Republican, you presumably believe that center-left policies — higher taxes on top incomes, a big subsidized expansion of health insurance, tighter financial regulation — are bad for the economy. But even if you think the Obama economy should have been better, the fact is that we’ve added 11 million private-sector jobs; stocks are way up; inflation and interest rates have stayed low; the budget deficit has withered away.

So it’s not a disaster, and there’s no reason to believe that a Clinton economy would be a disaster either. Meanwhile, Mr. Trump is talking about wildly irresponsible tax cuts, renegotiating debt, and ripping up trade agreements.

Moving up the scale of importance, what about national security? Even if you think that President Obama could have gotten better results by bombing more and talking less, there’s just no way to paint Mrs. Clinton — who has the support of many retired military leaders — as some kind of pushover for terrorists and foreign aggressors. Meanwhile, her opponent talks about abandoning NATO allies if they don’t pay up and seems fine with Russian adventurism in Ukraine.

Most important of all is the question of democracy at home.

I know, conservatives like to complain that Mr. Obama has overstepped his authority by, say, using administrative discretion to delay some provisions of the Affordable Care Act. But let’s be serious: no non-crazy person, even on the right, thinks that this president is acting like a dictator, or that the woman he wants to succeed him would threaten basic liberty. On the other side, anyone watching her opponent has to be very, very worried about his authoritarian streak.

The bottom line is that even if you don’t like Mrs. Clinton or what she stands for, it’s hard to see how you could view her possible victory with horror. And it’s hard to see how you could view Mr. Trump’s possible victory any other way.

How, then, can rational Republicans justify supporting Mr. Trump, or even remaining neutral, which is in effect giving him half a vote?

For rank-and-file Republicans, it’s presumably about feelings. Having spent so many years denouncing Democrats in general and Mrs. Clinton in particular, they have a hard time admitting that someone else could be much, much worse. But democracy isn’t about making a statement, it’s about exercising responsibility. And indulging your feelings at a time like this amounts to dereliction of your duty as a citizen.

And whatever one may say about ordinary voters, the real sinners here are Republican leaders — people like Paul Ryan and Mitch McConnell — who are actively supporting a candidate whom they know poses a danger to the nation.

It’s not hard to see why they’re doing this. Opposing their party’s nominee, no matter how awful he is, would probably end up being a career killer.

But there are times when you’re supposed to put such considerations aside. The willingness of some people who know better to support Donald Trump is understandable; it’s also despicable.