MINNEAPOLIS — A fired-up President Trump lashed out against Democrats at a combative campaign rally on Thursday night, deriding them as “very sick and deranged people” who were only investigating him for abuse of power in order to “erase your vote.”
Facing impeachment in the House, Mr. Trump took his case to his core supporters, arguing that Democrats were trying to overturn the 2016 election because they knew they could not beat him in 2020. He singled out former Vice President Joseph R. Biden Jr. as nothing but a toady for President Barack Obama.
“He was only a good vice president because he knew how to kiss Barack Obama’s ass,” Mr. Trump said, a line that drew huge roars of approval from the crowd.
In his first campaign rally since Speaker Nancy Pelosi declared the formal beginning of an impeachment inquiry last month, Mr. Trump was as raw and rancorous as ever, targeting individual Democrats in highly personal terms that no presidents has used in public and presenting himself as a victim of a partisan conspiracy.
“From Day 1, the wretched Washington swamp has been trying to nullify the results of a truly great and democratic election,” Mr. Trump told a crowd of about 20,000 at the Target Center in Minneapolis, one of the most Democratic cities in the country. “They want to erase your vote like it never existed; they want to erase your voice, and they want to erase your future.”
He fired off insults in rapid succession at F.B.I. agents, lawmakers and journalists who he said were out to get him. “She’s either really stupid or she’s really lost it — or maybe there’s a certain dishonesty in there,” he said of Ms. Pelosi.
Representative Ilhan Omar, Democrat of Minnesota, who is one of his favorite targets, is an “America-hating socialist” who married her brother in order to come into the country, he said. (No proof has emerged substantiating the marriage claim.)
He went local in targeting the city’s Democratic mayor, Jacob Frey, who drew the president’s ire this week for seeking reimbursement for the cost of extra security required for the rally. “You got a rotten mayor,” Mr. Trump said. “You’ve got to change your mayor.”
But no Democrat came under as much fire as Mr. Biden, one of the leading Democrats bidding to challenge him next year. It was Mr. Trump’s efforts to pressure Ukraine’s president to come up with damaging information about Mr. Biden that prompted the House impeachment inquiry that now threatens his presidency.
Mr. Trump maintained he was interested only in uncovering supposed corruption by the former vice president and his younger son, Hunter Biden, who made $50,000 a month serving on the board of a Ukrainian energy company at the same time his father was working on Ukraine policy for the Obama administration.
In scathing terms, Mr. Trump mocked Hunter Biden, who struggled for years with alcohol and drug abuse and was discharged from the Navy Reserve after failing a drug test. Calling him unqualified for the energy company post, Mr. Trump declared that Hunter Biden was “not too smart” and added, “Hunter, you’re a loser.”
He noted that Hunter Biden had been out of the public spotlight in the past couple of weeks as the president and his supporters have sought to make him a political liability for the former vice president.
“Whatever happened to Hunter?” Mr. Trump demanded. “Where the hell is he? Where’s Hunter?” Turning to a group of supporters, the president said, “Hey, fellas, I have an idea for a new T-shirt.” It should say, “Where’s Hunter?” he added.
Mr. Trump was proudly on offense all night, cheerfully using the word “hell” repeatedly while mocking those who say he should watch his language. “I’m energized,” he told the crowd.
At another point, he reveled in his ad hoc blasts at his enemies. “Isn’t it much better when I go off script?” he asked.
The rally, the first of three in the next week, came on a day of rapidly advancing developments in the impeachment inquiry and related matters.
Energy Secretary Rick Perry was subpoenaed on Thursday for records that could shed light on any role he may have played in Mr. Trump’s attempts to pressure the Ukrainian government. Lev Parnas and Igor Fruman, two of associates of Mr. Trump’s personal lawyer Rudolph W. Giuliani, were indicted on campaign finance charges.
And Mr. Trump told reporters that the man just announced as his outside counsel, Trey Gowdy, could not start in that position until January because of “lobbying rules,” even as House Democrats hope to have an impeachment vote wrapped up by the holidays.
Despite the fast-moving inquiry unfolding in Washington, Mr. Trump showed that he, too, was barreling forward in his re-election campaign, using impeachment as fuel to energize his hard-core supporters while trying to expand the electoral map.
This time, his campaign is pouring resources into a state with the hopes of putting Democrats on defense and projecting confidence that they have more paths to re-election than simply recreating the winning map from 2016. Mr. Trump lost Minnesota by 1.5 percentage points to Hillary Clinton in 2016, despite having no campaign staff on the ground and barely setting foot in the state.
“We are going to win this state,” Mr. Trump said as he took the stage Thursday night. “This feels like the day before the election.”
The president’s decision to visit Ms. Omar’s backyard was also a show of confidence, challenging a local congresswoman in her home state.
“How do you have such a person representing you in Minnesota?” he asked the crowd, calling her one of the “big reasons” that he would win re-election.
He bemoaned the fact that so many Somali refugees had been allowed to resettle in Minnesota and boasted that he had closed the door to many foreigners seeking protection in the United States. “I have reduced refugee resettlement by 85 percent,” he said.
Outside the Target Center, Trump protesters clashed with Trump supporters, their shouting and cursing escalating as the president took the stage. Many said the longtime Democratic state suddenly felt like a battleground, and strangers approached each other to pick fights.
“Tell me why you like him,” one man yelled at a nearby Trump supporter.
Criticized by another protester for the president’s white supremacist undertones, the Trump supporter replied, “I could have 100 black people with me if I wanted to.”
Cameron Russell, 26, of Minneapolis, a donor support technician who is black, voiced his skepticism: “Yo, man — pull them up. Call them up.”
Then Mr. Russell recognized the Trump supporter, who is white, as a high school classmate.
“I thought you were cool,” Mr. Russell said to him.