All the political action in Iowa may be among Republicans, but President Biden’s campaign on Monday sought to get a piece of the action, sending three top surrogates to Des Moines to promote his agenda and trash his potential opponents.

Gov. J.B. Pritzker of Illinois, Senator Tina Smith of Minnesota and Jeffrey Katzenberg, a Hollywood megadonor and campaign co-chairman, all made their case for re-electing Mr. Biden before a dozen TV cameras and a gaggle of journalists in a conference room at the Iowa Events Center.

Mr. Pritzker said there was no difference between former President Donald J. Trump and his G.O.P. rivals, Ms. Smith warned that Republicans would ban abortion nationwide if they won back the White House, and Mr. Katzenberg did a victory lap on the campaign’s latest fund-raising announcement.

“Tonight’s contest is simply a contest of whether you like MAGA in its original packaging or in high heels or with lifts in their boots,” Mr. Pritzker said, jabbing at Nikki Haley, the former South Carolina governor who quipped during a debate about wearing heels, and at Gov. Ron DeSantis of Florida, who has been suspected of wearing lifts in his shoes.

Beyond cracks about the Republican candidates’ footwear, the Biden surrogates did not share much new information about the re-election campaign or the president’s thinking. Mr. Pritzker fended off questions about immigration policy and the Supreme Court case concerning Mr. Trump’s eligibility to be on the ballot, while Mr. Katzenberg declined to engage in a debate over whether the Biden campaign is too focused on coastal supporters.

Instead, they sought to convey their argument that the future of the nation would be at risk if Mr. Trump were re-elected.

“The campaign is running an operation like our democracy depends on it,” Mr. Katzenberg said. “Because in some respect it does.”