In Israel, people active in causes the Adelsons have aided said that Ms. Adelson was even more fervid in her views than her husband.

If we are to believe Michael Lewis Arthur Meyer, who heads a group called Veterans on Patrol, and the conspiracy theories now circulating in the more fervid nether parts of the internet, this is a “child sex camp” run by traffickers or drug cartels.

This has made opposition to a more equal, multiethnic society more fervid among those who feel their privileges threatened.

There are loons on the left, too, of course, but the liberal establishment has simply never given its imprimatur to preposterous conspiracy theories, and research about belief in dubious conspiracies confirms that there are many more fervid American conspiracists on the right.

But Democratic leaders have rebuffed the more fervid among the rank and file; they do not want to squander their credibility by looking too politically motivated.