Suppose President Donald Trump has some basis for saying that the Barack Obama administration abused its investigative powers to go after him and his associates last year. The possibility cannot be ruled out at this point. But Trump and his aides are making it hard to take the accusation seriously.

On Saturday morning, Trump tweeted that he had just learned that Obama had his wires tapped in Trump Tower right before the election. Neither he nor his aides offered proof. The claim has now been denied by a spokesman for the former president, by FBI Director James Comey and by former Director of National Intelligence James Clapper.

Some people greeted Trump’s claim credulously. The president’s cheering section believed him, of course. So did some of his most bitter foes. Former Democratic National Committee chairman Howard Dean took it as a given that Trump was right about being wiretapped, but said that it proved that a judge had “found probable cause that Trump was engaging in criminal activity.”