President Donald Trump, having elected to skip the White House Correspondents’ Dinner for the second year in a row, continued on Saturday evening to train his ire on Senator Jon Tester (D-MT), who he blames for derailing the nomination of White House physician Ronny Jackson to run the Department of Veterans Affairs.

“Tester started throwing out things that he’s heard. Well, I know things about Tester that I could say, too,” Trump threatened at a rally in Washington Township, Michigan. “And if I said them, he’d never be elected again.” (Trump did not say what these things were).

Tester, the top Democrat on the Senate veterans’ affairs committee, contended this past week that there his office had been told of numerous allegations of inappropriate workplace behavior by Jackson, including excessive drinking on the job and over-prescribing medications. Those accusations led Jackson to withdraw his nomination for the position.

While President Trump has singled out Tester, both in a series of morning tweets on Saturday and at his rally, for upending the nomination process, several Republican senators involved in the vetting process told The Daily Beast that the White House had not done a good enough job preparing Jackson for the nomination.

Tester had the support of his colleague, Sen. Johnny Isakson (R-GA), in investigating the allegations, but only the Montana Democrat, who is up for re-election this year, was singled out for Trump’s wrath.

“What Jon Tester did to this man is a disgrace,” Trump said.

Earlier on Saturday, Trump tweeted that the Secret Service had found the allegations previously released by Tester’s staff to be untrue. What the Secret Service actually said on Friday, however, was that they had no record of a specific allegation, first reported by CNN, which claimed that during an overseas trip in 2015, Jackson drunkenly banged on the door of a female colleague to the point at which agents had to calm him down.

"Over the last 48 hours, media outlets have alleged that U.S. Secret Service personnel were forced to intervene during a Presidential foreign travel assignment in order to prevent disturbing (former) President Barack Obama,” the Secret Service said in a statement. “The Secret Service has no such record of any incident; specifically, any incident involving Rear Admiral Ronny Jackson.”

Separately on Friday, the White House said a review of Jackson’s vehicle records found no indication that he “wrecked” a car after drinking at a Secret Service party, a claim that was included in the release of allegations from the Senate.

“The great people of Montana will not stand for this kind of slander when talking of a great human being,” Trump tweeted on Saturday. “Admiral Jackson is the kind of man that those in Montana would most respect and admire, and now, for no reason whatsoever, his reputation has been shattered. Not fair, Tester!”

Tester is one of ten Senate Democrats up for reelection in November in states that President Trump won in 2016.

Throughout the rest of the president’s free-wheeling address, he discussed how much he likes French President Emmanuel Macron, said that Republicans would retain the majority in the House of Representatives in November and, of course, referenced Kanye West.

“Kanye West gets it,” Trump said.

Besides Tester, the president reserved the greatest deal of his anger for former FBI Director James Comey, who has recently embarked on a book tour.

Describing one of the more pivotal moments in his presidency, Trump called Comey a “liar and a leaker” and said “I did you a great favor when I fired this guy.”