President Donald Trump lashed out Friday at Democrats in the House for their vote this week formalizing the impeachment inquiry into his conduct, calling it “an attack on democracy itself.”

Democrats are “disgracing themselves and bringing shame upon the House of Representatives,” Trump charged during a rally in Tupelo, Mississippi in support of the state’s Republican candidate for governor. “They’ve been plotting to overthrow the election since the moment I won,” he told the packed crowd.

The rally came a day after Democrats voted to formalize the investigation into whether Trump abused his office and compromised national security when he asked the president of Ukraine to investigate one of his political rivals.

Aggrieved and feeding off the energy of the crowd, Trump repeatedly defended himself against what he called the “deranged impeachment witch hunt” and accused Democrats of doing anything to take him down and invalidate the results of the 2016 campaign.

At one point, Trump mockingly impersonated former Vice President Joe Biden. Trump’s efforts to get Ukraine to investigate Biden and his family led to the impeachment inquiry.

Still, Trump insisted — despite polling to the contrary — that the investigation is helping him politically and will hurt Democrats come 2020, telling his crowd that “we’ve never had greater support than we have right now.”

“While we’re creating jobs and killing terrorists,” he said, “the Democrat Party has gone completely insane.”

Trump also celebrated the news that Beto O’Rourke, one of the Democratic candidates running to replace him, has dropped out of the race.

Trump unleashed a slew of insults, calling O’Rourke “pathetic,” ”nasty” and a “poor bastard.”

“He made a total fool of himself,” Trump said, mocking an interview in which O’Rourke said he was born for the job.

“He said that he was born for it, like he was born from heaven, he came down,” Trump told his crowd. “Anybody who says they were born for this, they’re in trouble.”

Trump was in Mississippi trying to shore up support for Lt. Gov. Tate Reeves, who is locked in a tight race to replace term-limited Republican Gov. Phil Bryant in next week’s off-year election.

The race between Reeves and Democrat Jim Hood for the open seat is considered the state’s toughest governor’s race in nearly a generation.

Trump expressed surprise that the race is a close one but promised, “We’re going to send a signal by sending a terrific new Republican governor to Jackson.”

Even though the state’s Democratic nominee for governor lost by 34 percentage points four years ago, Democrats in this conservative Deep South state think they have a shot this time with Attorney General Hood as their nominee.

Hood, 57, who is serving his fourth term, has been elected by wide margins in his previous races and is currently the only Democrat to hold statewide office.

Trump tried to tie Hood with national Democrats, saying he’s “not the kind of guy” Mississippi needs.

Trump also celebrated the killing of Abu Bakr al-Baghdadi, the former leader of the Islamic State Group, calling him “a savage and soulless monster.”

But he also complained that he hadn’t gotten enough credit for the killing.

“Conan the dog got more publicity than me,” he said, referring to the dog that played a key role in the Syria raid.

The rally is one of a handful of events Trump and Vice President Mike Pence will be holding in the coming days to try to bolster Republican candidates running in gubernatorial elections.

Trump is scheduled to travel to Kentucky Monday to campaign for incumbent GOP Gov. Matt Bevin. He is heading to Louisiana on Wednesday to campaign for Republican gubernatorial candidate Eddie Rispone, who is trying to unseat incumbent Democratic Gov. John Bel Edwards.

Pence was in Kentucky Friday campaigning for Bevin and will travel to the Mississippi Gulf Coast Monday to campaign for Reeves, among other stops.

“It’s always good for the president to help out Republicans up and down the ticket,” said Rick Gorka, a spokesman for Trump’s campaign and the Republican national party. “He needs reliable partnerships and strong leaders in the states in order to continue to enact his policies, so this is a way to lend his support to Tate Reeves to close out this election strong.”

Reeves has sought to tie Hood as closely as possible to national Democrats, such as House Speaker Nancy Pelosi, who are deeply unpopular in a state that voted heavily for Trump in the last presidential election.

Hood says Reeves and other Republicans have underfunded schools and ignored the financial plight of rural hospitals while giving tax breaks to big businesses.

Hood has not invited national Democratic figures to Mississippi.

He’s running campaign commercials that show him with his family, his pickup truck and his hunting dog, Buck.

In one, Hood unpacks a rifle and says that “Tate Reeves and his out-of-state corporate masters” are spending money on a “bunch of lies.”

Reeves has faced some enthusiasm problems of his own in the Republican party. He was forced into a runoff with Bill Waller Jr., former chief justice of the Mississippi Supreme Court.

But Gorka said the party was confident heading into Tuesday’s Election Day.

“We’re looking at a strong possibility of winning in Mississippi, but also flipping seats in Louisiana and keeping the one in Kentucky,” he said. “So the way we always approach any election is we invest to win, both with data and infrastructure, but also with the most precious resource, the president’s time, to make sure that we’re getting the most bang for our buck.”