Bernie, Mayor Pete, Biden — it doesn't matter who wins the Iowa Democratic caucuses because not one of them stands a chance against Donald Trump.

At least that was the general attitude among many Trump supporters who filled the rafters of Drake University in Des Moines Thursday night, just days before the Iowa caucuses officially kick off the presidential nomination process.

"None of them," said Ted Reeve, a home builder from Des Moines, when asked which Democratic candidate would give Trump the most trouble in the general election. "Trump will win in a landslide. I don't think it will even be close."

"None of them," was by far the most popular answer given by Trump supporters when asked who posed the greatest challenge to Trump.

But even if his supporters here don't believe these Democrats pose a threat, Trump's appearance in Iowa is no accident.

While he won the state handily in 2016, it could be competitive this year, said Iowa State University political science professor David Peterson.

Iowans Ted and Patty Reeve believe Trump should have no problem winning a second term, regardless of which Democratic nominee he faces. (Mark Gollom/CBC)

The state's economy has been slowing down, even as growth is strong in the rest of the country, said Peterson. The trade war has been particularly hard on Iowa farmers, who are quite good at seeing the direct link between federal policy and their bottom line, he said.

That means Trump's appearance, days before the caucus, is to remind Iowa Republicans and Trump-leaning independents why they like him, Peterson said.

The crowd at Drake University's Knapp Center certainly needed no reminding. The thousands who had crammed inside — a near sea of red MAGA-like ball caps dotting the arena — loudly showed their support when the U.S. president took the stage. Some had waited in the cold for hours to get in, with a few, according to the Des Moines Register, camping outside the day before.

Hundreds of others who couldn't get inside stood outdoors, watching Trump's speech on a big screen. Not all were fans. Dozens of protesters also stood nearby to condemn the president.

Impeachment riles base

While Trump's presidential fate was being debated in Washington, D.C., through an impeachment trial, here in Iowa, the topic has angered his base, seemingly ensuring they will come out and vote.

It's totally political," said John Golnick. "The Democrats have hated Trump even before he was elected."

Many supporters of Trump, who has been accused of withholding aid to Ukraine in order to persuade government officials to investigate potential political rival Joe Biden and his son Hunter, believe he didn't do anything wrong — and certainly nothing that would necessitate impeachment.

"They're getting people riled up, as they say in southern Iowa," said Roger Burdett. "They're helping him get elected."

In fact, Trump's competition is so weak that Burdett predicted the president will win an even larger mandate in the 2020 presidential election.

Take Bernie Sanders, for example, and what seems to be his growing momentum in the Democratic nomination race. Many at the rally agreed Sanders and Trump share at least one thing in common — a real passion and enthusiasm among their core supporters.

Still, "he doesn't have a chance in hell of winning," Burdett said of Sanders.

While Bernie Sanders, a senator from Vermont, may have some momentum in the polls, Steve Ward, above, a rancher from Wyoming, dismissed him as a viable challenger to Trump. (Mark Gollom/CBC)

Steve Ward, a rancher from Wyoming who drove in to see Trump, also dismissed the Vermont senator as a viable challenger. "Good luck Bernie," Ward said, smiling. "Bernie just don't have it."

Reeve's wife, Patty, who is an accountant, summed up what many of Trump supporters thought of Sanders's chance of victory in a general election: "I think his socialist views are just way too far left."

Others also dismissed Biden, saying Americans would look unfavourably at his record as vice-president and give him a big pass, although Iowan Brian Belew said a Trump-Biden matchup "would be fun to watch."

But there was one Democratic candidate, mentioned a few times, who seemed to give them slight pause: Pete Buttigieg.

Kelly Bennett, a financial planner from Antkenny, Iowa, believed the former mayor of South Bend, Ind., would have the best chance to compete against Trump.

Roger Burdett said he believes Trump will win an even larger mandate in November during the 2020 presidential election. (Mark Gollom/CBC)

"I think that he has common sense appeal. I think he's a little more moderate," Bennett said. "I think he can dip into the Trump vote, the moderate, common sense swing vote that went Trump's way last time.

"I think he could get some of that to swing back the other way."

Trump made mention of the Democratic candidates during his Iowa rally Thursday, mocking their names and referring to them as "the radical Democrat socialists who are right down the street."

He also wondered out loud, half-jokingly, if Hillary Clinton took another run at the presidency, who would give him the hardest time: her, Sanders, Buttigieg or Biden?

Trump supporter Belew had an answer for that. "I cannot think of anyone."