Donald Trump, the obnoxious and, as of this week, noxious candidate for the Republican nomination, has a simple theory about why he is leading in many polls: "Every time things gets worse, I do better," he boasted to supporters on Saturday in Iowa.
By "worse," Mr. Trump was referring to the recent terrorist attacks in Paris and San Bernardino, Calif. A frightened public can be easy pickings for a demagogue, and two days later he put his theory to the test by calling for "a total and complete shutdown of Muslims entering the United States."
It didn't work. Instead of doing better, Mr. Trump found himself under siege. His opponents jumped on his racist ban on Muslim immigration, accurately calling it unconstitutional and un-American. Republican state governors and other party faithful were equally vehement in their denunciations, as were the White House, the Prime Minister of France and the governments of several Muslim countries.
By Tuesday, you could tell it was getting to Mr. Trump: He used Twitter to hint that he might leave the Republican Party and run as an independent.
If only. By exploiting the fear and hatred of Muslims, Mr. Trump has moved the Republican Party into the dark territory of radical, far-right politics. He has made it clear that, as president, he would implement the kind of racist policies favoured by virulently nationalist anti-immigration parties. And he is forcing his party to either endorse his racism or lose him as a candidate.
If Republicans had any idea of what they stand for any more, they would kick him out of the race. But this is a party that is barely hanging onto its soul. From the Tea Party insurgency that began in 2009 to the wackiness of many of the candidates in the current race, it is becoming unrecognizable as a mainstream political entity. It could go a long way toward restoring its credibility by ditching Mr. Trump, but it doesn't have the required self-awareness.
And so, by keeping Mr. Trump in the race, the Republican Party has become unfit to lead the country. Heightened times like ours require leaders who propose rational solutions in keeping with the values of a constitutional democracy, not weak demagogues who betray those values at the first sign of trouble.