Charles Lipson: The most profound attacks on Donald Trump are that his presidency is illegitimate and that he wants to destroy our constitutional structure. The Democrats have leveled those accusations for four years, accompanied by charges he is a wannabe dictator, elected thanks to his good buddy, Vladimir Putin. These frenzied charges, we now know, were invented and paid for by Hillary Clinton’s campaign, and then funneled to the U.S. government through the FBI, Department of Justice, and State Department. Meanwhile, the CIA and then the FBI were busy spying on the Trump campaign (and, later, in the FBI’s case, on the Trump presidency), trying to find “collusion” with Russia. Their relentless effort led to the appointment of Special Counsel Robert Mueller, whose partisan team knew almost immediately there was no proof of these damning allegations. They should have told the public immediately. Instead, they spent the next two years trying -- and failing -- to catch President Tr...