Aides and Trump allies said they believe the findings will bolster the credibility of the president — who traffics in untruths and conspiracy theories — while also undermining Democrats, some of whom have predicted that Trump would be found guilty of conspiring with the Russians and obstructing Mueller’s investigation.

One former White House official said the Democrats have “just handed the Trump campaign the greatest election issue in modern political history, on a silver ­platter.”

Douglas Brinkley, a presidential historian at Rice University, said: “Trump actually kind of has inoculation now against other charges against him because he was able to prove his innocence here. It allows Donald Trump to build his narrative about how the news media and the Democrats created this whole Russia collusion hoax, in Trump’s mind.”