MINNEAPOLIS – President Donald Trump didn't waste a moment Thursday before he railed against the "insane impeachment witch hunt" in his first campaign rally since House Democrats launched an impeachment inquiry against him.

Trump told a crowd of supporters at the Target Center in Minneapolis that "corrupt politicians and the radical left got rich bleeding America dry and they knew my election would finally end their pillaging and looting of our country."

"From day one the wretched Washington swamp has been trying to nullify the results of a truly great and Democratic election," a defiant Trump said in searing remarks that included attacks on Joe Biden, Nancy Pelosi and Minnesota's own Rep. Ilhan Omar.

“They want to erase your vote like it never existed. They want to erase your voice and they want to erase your future. But they will fail because in America the people rule again," he added.

House Democrats launched an impeachment inquiry to look into whether Trump improperly used the power of his office to further his own political aims by pushing Ukraine to investigate Biden. During a phone call on July 25 phone call, Trump asked Ukrainian President Volodymyr Zelensky to look into Biden but he has insisted there was nothing improper about the call.

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Trump described the inquiry Thursday night as "the Democrats' brazen attempt to overthrow our government."

The president's rally comes a day after Fox News released a poll that found 51% of voters support impeaching Trump and removing him from office, a new high since the House began an impeachment inquiry into allegations he pressured Ukraine to investigate Biden and his son Hunter.

He said he was under attack because he appeared to be ahead in the election, but acknowledged that recent polls showed otherwise.

"Polls are no different than crooked writers," he said. "They're crooked polls."

Earlier Thursday on Twitter, he said of the poll, "Whoever their Pollster is, they suck."

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Minneapolis, a sanctuary city known for its left-leaning politics, is also home to Omar, a Somali-born freshman lawmaker the president has repeatedly lashed out at on Twitter and has cast as one of the faces of the Democratic party. Omar, who won 78% of her district in 2018, enjoys wide support in her hometown of Minneapolis.

"How do you have such a person representing you in Minnesota?" Trump asked the crowd, calling Omar "an America-hating socialist."

Trump called her "a disgrace to our country," adding "she is one of the big reasons that I am going to win and the Republican party is going to win Minnesota."

Omar acknowledged in a tweet Thursday she expects Trump to attack her, but added it wouldn't stop her from her work in Congress.

The president also criticized the government for allowing a large share of Somali refugees to settle in Minnesota, to which the crowd responded with loud boos.

He vowed to give communities greater say in refugee policy before boasting about reducing the refugee resettlement program. Minnesota, which is home to a large Somali immigrant population, also has the largest number of refugees per capita nationwide, with 13% of the country's refugees, according to U.S. Census data.

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Protesters trickled onto First Avenue in front of the venue throughout the afternoon, braving the rain to rail against the president's anti-immigration rhetoric and what his critics see as his divisive rhetoric.

At one point, protesters began chanting "lock him up," a reference to the 2016 chant that Trump supporters used when Trump would criticize his political rival Hillary Clinton.

Emilie Robinson, 32, said Trump "stands for everything we don’t stand for and my message for him is I don’t stand with you.”

“Minneapolis is a place where we really support and protect our immigrant population and we have really progressive laws that protect women’s bodies. We have our own problems but we have a really good track record,” the Minneapolis small business owner said.

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"It's a total abuse of power," Bruce Wagner said of Trump's request of Ukraine to investigate Biden, a move that led to the impeachment inquiry.

Wagner, who stood in the rain holding a sign that read, "The Lyin' King," with Trump's face superimposed on a lion, said he "lies about everything."

"We want a dialogue with everyone, but we need to be down here to stand up to Trump," the Apple Valley, Minn., resident said.

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But the battle for Minnesota began well before Omar was elected to the House of Representatives in 2018. Minnesota, which hasn't supported the Republican nominee for president since Richard Nixon in 1972, narrowly voted for Hillary Clinton by 1.5% in 2016. Trump, who lost by a margin of 44,000 votes, has indicated he thinks he can close that gap in 2020.

That multi-prong push for Minnesota voters included a discussion with second lady Karen Pence and Lara Trump, the president's daughter-in-law, at a "Women for Trump" event Wednesday night. The room was overflowing with pink and red Make America Great Again hats as women cheered. Pence and Trump urged supporters to talk to their neighbors about casting their ballot for Trump in 2020. Vice President Mike Pence also visited a company that makes roadway signs in nearby Lakeville, Minn., ahead of the rally.

Kayleigh McEnany, the campaign's national press secretary, pointed out Minnesota was the second closest blue state Trump lost in 2016, after New Hampshire.

"If you look at the mold of Minnesota, it's very similar to Wisconsin or Pennsylvania, especially in the breakdown of the counties," she said, noting the president won the latter two states in 2016. "We're going to pull out a victory this time."

According to Republican National Committee officials, the campaign has built out a training program since 2016 that counts nearly 1,000 local volunteers across the state as part of the Trump Leadership Victory Initiative. Republicans have focused much of their attention on rural parts of Minnesota, where the GOP flipped two congressional seats during the 2018 midterm election.

Minnesota Democrats have acknowledged local GOP efforts, noting in a Twitter thread donation drive on Monday that the state has been trending more red in previous presidential elections.

"The Trump campaign is staffing up in Minnesota in ways we’ve never seen before, and frankly we just can’t keep up," one Tweet read.

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Ahead of his visit, Trump amplified his attacks on both Omar and Minneapolis Mayor Jacob Frey, a vocal critic of Trump who drew the president's ire after city officials told the venue where the rally is taking place it would be responsible for footing the bill of $530,000 in security costs related to the visit. The venue, Target Center, tried to pass off the bill to the Trump campaign, which responded by threatening to sue for breach of contract. Trump weighed in on the fracas on Twitter on Tuesday, calling the mayor "lightweight" and calling on his supporters to "dump" both Frey and Omar.

But Barb Koy said the mayor doesn’t speak for all the people of Minnesota in his efforts to tangle Trump’s visit.

“He only lost this state by 44,000 votes,” said Koy, a Bloomington, Minn., resident. “I think he’s going to flip this state.”

Koy said she thinks the impeachment inquiry is just “another game by the Democrats.”

“Everybody is tired of it. I know people who voted blue and they’re voting red now because they’re sick of it,” she added.

The president also took issue with a recent Minnesota Police Department policy change barring off-duty officers from wearing uniforms to political events. The police union responded by designing "Cops for Trump" shirts that officers plan to wear and sell at the event.

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Winning Minnesota would be an uphill battle for the president. Trump's net approval ratings have dropped from +3 in January 2017 to -11, according to Morning Consult.

Minneapolis resident James Allison said he's not convinced by the numbers just yet.

"I've talked to a lot of people who have voted Democratic or typically vote Democratic, and they're voting for Trump this time around," the 38-year-old said. "There's a whole host of reasons that people are voting for him, but hate and fascism are not among them."

Becky Andre, a resident of St. Bonifacius, Minn., said she’s behind the president because of what he’s done for the country but also how he energizes his supporters.

“It’s a feeling I have, it’s not just so much every statistic, it’s also just a feeling I have,” she said.

But Jackie Craig, who works with Women's March Minnesota and attended Thursday's protest, said she believes his strategy in Minnesota isn't working.

"I think he's actually bringing people closer together, and people here more understanding of each other's differences and supporting one another," she said. "And that diversity and inclusiveness will be on display outside the rally."