An August 2016 column appearing on RealClearPolitics and The Daily Beast summarized the problem.
How Paul Krugman Made Donald Trump Possible
Liberal pundits write viciously about Trump. But they wrote viciously about Romney, McCain, Bush… and they wonder why people outside their circle stopped listening.
08.05.16 1:00 AM ET
His convention was called "one of the worst ever." Chris Matthews deemed him "dangerous" and "scary," Ellen DeGeneres said "If you're a woman, you should be very, very scared." His opponent ran an ad against him portraying him as uniquely dangerous for women. "I've never felt this way before, but it's a scary time to be a woman," said a woman in the ad.
He was frequently called a "bully," "anti-immigrant," "racist," "stupid," and "unfit" to be president.
I'm referring, obviously, to the terrifying Mitt Romney.
Take Paul Krugman in The New York Times. In Tuesday's column he wondered how any "rational Republicans justify supporting Mr. Trump." He concludes it's about "feelings," a dismissal of legitimate arguments many people, both Republicans and not, have against Hillary Clinton. But no one is more feelings-based than Krugman when it comes to Republicans. If he wants to know how people can take Donald Trump seriously, he should take a hard look at himself.
In 2012, Krugman called Mitt Romney a "charlatan," pathologically dishonest, and untrustworthy. He said Romney doesn't even pretend to care about poor people and wants people to die so that the rich could get richer. Romney is "completely amoral," "a dangerous fool," "ignorant as well as uncaring."I've attended academic conferences at which keynote and plenary speakers insulted not only Republicans, but also Democrats considered too close to their GOP colleagues. When academics (and Krugman relies on his standing as a professor to support his writing persona) toss about accusations that anyone they oppose is motivated by hate, greed, and is otherwise evil, there is no opportunity for civil discourse on policy differences.
In March, Krugman had a column called "Clash of Republican Con Artists." In it, he called Trump's foreign policy more reasonable than that of Marco Rubio or Ted Cruz and said he's just as terrified of either of those men in the White House as he is of Trump. He wrote: "In fact, you have to wonder why, exactly, the Republican establishment is really so horrified by Mr. Trump. Yes, he's a con man, but they all are. So why is this con job different from any other?"
Yet a few weeks ago Krugman wondered how Republicans could rally around Trump "just as if he were a normal candidate." It was exactly Krugman who normalized him! What makes Donald Trump normal to so many is that they've heard all the hysteria from people like Krugman before. If you use the most vile language available on a good man like Romney, or on real candidates like Rubio and Cruz, you find you have none left for the Donald Trumps of the world—and no one is listening to you anyway.
If every Republican is always unfit for the presidency then Trump is no different and it shouldn't be surprising that rank-and-file Republican voters are lining up behind him. They know there aren't actually any Republicans of which the media approves.
Lumping Ted Cruz with Marco Rubio and Mitt Romney is a mistake. Cruz uses the same hyperbole against his opponents, even within the same political party, that my academic colleagues employ. The perspective differs, yes, but opposition is covered by a blanket dismissal.
If progressives are going to complain about the ridiculous claims of Donald Trump or Ted Cruz, they must also monitor their own language and claims about moderate voices with which the progressives disagree.
You cannot clamor for "reasonable conservatives" if only weeks before you were calling all conservatives unreasonable.
Rhetoricians should ask how political discourse across the spectrum helped inoculate voters against evidence and reason. I'm convinced that calling moderates names and using hyperbole against them has had devastating consequences for the United States and other Western democracies.