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DES MOINES, Iowa — While the Senate debated his removal from office, President Donald Trump jabbed at his Democratic opponents here as some campaigned to replace him just miles away.

Trump focused most of his attacks on former Vice President Joe Biden and Sen. Bernie Sanders, I-Vt. — both leading the Democratic presidential pack — while expressing disbelief at his impeachment trial back home.

"We are having probably the best years that we have ever had in the history of our country. And I just got impeached. Can you believe these people? I got impeached. They impeached Trump," he said. "No, that's not gonna work. Watch. Just watch."

Iowans hold their first-in-the nation caucuses Monday, and Trump has been increasingly seeking to rival key moments in the Democratic contest with rallies of his own. And while his impeachment trial has raged in Washington, he's looked for opportunities to tout his economic achievements, holding two trade deal signings in the past two weeks and stopping for an event in Michigan just before his Iowa rally.

Along with Thursday night's event, Trump's campaign has blanketed the state with 80 surrogates in the days before the Iowa caucuses, including Vice President Mike Pence, Donald Trump Jr. and numerous Cabinet and other White House officials who will be stumping for Trump in their personal capacities.

"We are going to defeat the radical socialist Democrats that are right down the street," Trump said Thursday, adding that Iowa voters have "had a front row seat to the lunacy and the madness of a totally sick left."

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"This is a radical left," he said.

As Biden traveled across the state between events, Trump declared that his campaign was on the ropes. "Now it's really over," he said, mocking Biden for misstating the name of the state he was visiting and drawing small crowds.

"That guy is so lost," he said.

After rattling off his economic successes and taking a victory lap on his recently signed trade deals, he asked the crowd, "What are you going to do, vote for Bernie?" At one point he played out how a general election debate over health care could go with Sanders.

Trump painted a doomsday scenario under a Democratic president. "If we don't win, your farms are going to hell," he said, claiming that under the Green New Deal supported by some of the 2020 contenders, "they want to kill your cows."

"That means you're next," he said.

The proposed legislation does not call for killing or banning cows.

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"Look, I can make this real easy," Trump told the crowd, musing that he could have just offered a few sentences to make his case. "Hello, Iowa. You have no choice. You have to vote for me. Otherwise everything you've built in your entire life will be gone. Goodbye, Iowa. Instead, I work my ass off up here! You think this is easy?"

The Trump campaign strategy behind deploying so many resources here has more than one goal, according to senior campaign officials: to suck up some of the oxygen and media attention that would otherwise be devoted to Democrats, to make a show of force — and to road-test the ground game.

The push in Iowa is also intended to help combat the wave of attacks by Democrats in what could be a swing state. While Trump won Iowa by about 10 points in 2016, the state went for Barack Obama in 2008 and 2012.

And, as is often the case at campaign rallies this cycle, 2016 was clearly still on Trump's mind.

"I feel badly because it is too late for her to get in," Trump said of his opponent that year, Hillary Clinton. "I kept hoping."