Des Moines, Iowa—Even as Republican senators were racing to acquit Donald Trump on charges of abusing his position in his first term, the president raced off to Iowa in fast pursuit of a second term. Trump jetted into the first caucus state Thursday on a dual mission. He would dutifully pump up turnout for Republican caucuses where he is sure to prevail, and he would rabidly attack the Democrats who seek to replace him.

The impeachment trial was mentioned, but only fleetingly, and with the confidence of a man who knows the fix is in. Dismissing the Democrats who have endeavored to hold him to account as the real threat to the country, Trump claimed that “they want to nullify your ballots, poison our democracy, and overthrow the entire system of government. That’s not happening.”

What is happening is an election, which—despite his braggadocio—worries Trump. So he came to Iowa to attack, smear, and ridicule his Democratic rivals with the fury of a man who knows he will be in a tight race this fall.

Even if he sounded like a November campaigner, however, Trump and his Republican allies were on a more immediate mission. Thousands of the president’s backers began lining up early on a cold Thursday morning—temperatures in the 20s, snow on the ground, overcast skies—for the 7 pm rally that packed Drake University’s 7,000-seat Knapp Center. The question was whether they would line up for Republican caucuses on Monday.

Trump, who has never really stopped campaigning here since he won Iowa in 2016, wants a show of strength at Monday night’s Republican gatherings. He’s not particularly concerned about the challenges posed by Republican rivals such as former Massachusetts Governor Bill Weld and former Illinois representative Joe Walsh, who have mounted amusing if not particularly robust efforts in the state. Walsh says, “Donald Trump has screwed Iowa. I mean, big time.” Weld says people who care about the Republican Party should use his candidacy as a vehicle to reclaim it from Trump. The Republican Party of Iowa’s Aaron Britt says the party’s Monday night caucuses will be “fair and transparent” and “relatively uncontested.”

Translation: Trump’s a shoo-in.

What really concerned Trump was the Democratic competition. While polls have generally put Vermont Senator Bernie Sanders ahead in anticipation of Monday’s caucuses, the Democratic competition with former vice president Joe Biden, former South Bend mayor Pete Buttigieg, and Massachusetts Senator Elizabeth Warren has been intense. In addition, Minnesota Senator Amy Klobuchar is generally seen as a contender who might nudge her way into the upper tier. Yet Sanders, Warren, and Klobuchar were in Washington Thursday night, listening to House impeachment managers and Trump’s lawyers answer questions about whether the president should be removed from office.

So Trump got to be the candidate in Iowa, where he seized a great big bully pulpit. On Thursday night, he took the bullying to extremes more reminiscent of a schoolyard than a presidential address. While a JumboTron setup outside the rally site urged attendees not to pick on protesters, the president was more than ready to pick on his Democratic rivals.

“During this campaign season, the good people of Iowa have had a front-row seat to the lunacy and the madness of the totally sick left,” declared Trump, who then dismissed his rivals as socialists who would raise taxes and ruin farms.

Mocking Warren, Sanders, and Biden, he shouted, “Let’s vote for Pocahontas, let’s vote for Bernie, let’s vote for Sleepy Joe!” While he stands accused of abusing his position in order to undermine Biden’s campaign, Trump used his rambling 90-minute speech to go down the line and attack all the major Democratic contenders.

Trump made fun of Buttigieg’s name: “How about But-Edge-Edge? They call him Mayor Pete. You know why? Nobody can pronounce his name.” He ridiculed former New York mayor Mike Bloomberg as “Mini Mike” and mocked the late-starting contender for not campaigning in Iowa. “What happened to Mini Mike? Where is he? He’s not running here. He’s skipping four or five states. Mini Mike,” grumbled Trump. “I’ve had him up to here.”

Trump spent a lot of time ripping Sanders as “crazy” for advancing his Medicare for All health care reform plan and for seeking to address the climate crisis. But he didn’t spend that much time talking about Sanders’s democratic socialism. Instead, Trump mislabeled the whole field as radical leftists and declared, “The Democrats will lose because America will never be a socialist country.”

Eventually, he was back to Biden, taunting the Democratic front-runner about the small crowds he is drawing in Iowa and about his mistaking Iowa for Ohio. “Sleepy Joe doesn’t even know what he’s talking about,” snarled Trump. “He’s so lost.”

The crowd ate it up. Every cheap shot was an applause line. Trump was not just speaking to the faithful Thursday night, however, or even to Monday’s Republican caucus-goers.

When the president gets to ranting and raving about the Democrats who propose to impeach him now or to defeat him in November, he goes to such extremes that it is easy to dismiss him. But that’s a mistake. The Des Moines rally was a trial run for November. Indeed, Trump was so focused on the fall race that it fell to Iowa’s Republican governor, Kim Reynolds, to make the election connection with the crowd—announcing that Iowans would back the president on February 3 and November 4. For Trump, Thursday night was an opportunity to try out lines of attack, which he will sharpen as the race moves beyond caucuses and primaries and Democrats settle on a nominee.

The Democrats need to recognize this, and to respond accordingly. That’s hard, because they are focused on beating one another. Biden, for his part, tried to turn the tables on Trump, with a speech delivered Thursday in the Des Moines suburb of Waukee just hours before the rally. The former vice president spoke of the “dark angry nation” Trump fosters with tweets and speeches. Biden’s message was blunt: “Health care. Climate. Guns. National Security. All these issues and more are on the ballot. But something else is on the ballot. Something even more important. Character is on the ballot. America’s character.” And, of course, he argued that he is the Democrat who is best positioned to upend Trump and Trumpism.

Yet it was another candidate who was far from Iowa, Elizabeth Warren, who provided the most energetic response to the president. Though she was stuck in Washington, Warren used even media platform she could find—TV, radio, Twitter, you name it—to speak to Iowans and people across the country about why the president has to go.

Her message was more sharply focused than Biden’s. Speaking as a juror in the impeachment trial and as a candidate, Warren told NPR:

I think the fundamental question here is about the corruption. Think about what this impeachment trial is really about. You know, who lies right at the heart of it is an ambassador, one ambassador who is a career ambassador, a public servant, the other one who got his spot not because he had any qualifications but because he gave a million-dollar contribution to the Trump inaugural committee. And Trump himself is the embodiment of this fundamental corruption in Washington, using our foreign aid as a country, our foreign policy, not to advance the interests of the United States, not to help us fight against Russian aggression in Ukraine but to advance his own political interests. That’s just wrong.

Warren may have been in Washington, and Trump may have been in Iowa. But Warren was engaging in the substantive debate that the Democrats need to have with this president.