Daniels argues that the deal is invalid because Trump, who denies the affair, never signed it. The legal battle has made Avenatti a celebrity on Twitter and cable news.
Avenatti has previously said the "number one question" facing Democrats in choosing a 2020 nominee is whether that person can beat Trump, and in an interview with the Des Moines Register, he touted his role as one of the President's most persistent and public critics.
"I think there's a huge appetite within the party for a fighter," he said, sketching out a potential campaign for the first time. "I think the party has yearned for a fighter - a fighter for good, if you will - for a significant period of time. And for many, I'm probably seen as that individual."
Avenatti told the paper that he is testing the presidential waters and that he decided to visit Iowa to listen to voters and to "do my homework" on the issues they care about most.
In an interview with the Washington Post, he said that he is a "strong supporter of universal Medicare for all," but that he will be studying up on some of the other policies that are coming up on the trail, such as last year's tax cut legislation and the President's tariffs on foreign goods.
"Over the years, I've developed the ability to digest a lot of information over a short period of time," Avenatti said. "I'm reading up on a number of issues. I'm meeting up with people who have far more experience with them than I have or will ever have. Rather than telling people what they want to hear, I'm asking them what they need."
Eighteen months before Iowans gather for presidential caucuses, plenty of Democrats are having the same conversations. Avenatti was joined at the Wing Ding by Maryland Congressman John Delaney, and entrepreneur Andrew Yang, both of whom began presidential campaigns last year; Delaney was set to finish his tour of all 99 Iowa counties tomorrow.
Americans "want their elected officials to do their job, make their lives and their futures more secure and prosperous," said Delaney.
"People have told me that the opposite of Donald Trump is an Asian man who likes math," said Yang, who is running on a promise to pay a universal basic income, referring to himself.
Congressman Tim Ryan, Ohio, also stopped by the Surf Ballroom while Congressman Eric Swalwell, California, Montana Governor Steve Bullock, former Housing and Urban Development secretary Julián Castro, and billionaire Tom Steyer had plans to visit the Iowa State Fair.
None are considered front-runners by party insiders, but few of the party's biggest names have made trips to Iowa.
Senator Bernie Sanders, Vermont, who narrowly lost the 2016 Democratic caucuses, has travelled to the state to sign books to support a congressional candidate who lost his primary. Senator Amy Klobuchar , Minnesota, who is up for re-election this year, has given two speeches in the state. Senator Elizabeth Warren, Massachusettes, and Senator Kirsten Gillibrand, New York, who are also on the ballot this year in their states, have not visited Iowa. Former vice-president Joe Biden's recent long book tour did not come to the state.
"I'm not that excited about the people I've heard about running," Jim Green, 50, a city employee in Cedar Rapids, said as he waited for the speeches to begin.
Iowa Democrats, who are optimistic about winning back the governor's mansion and two seats in Congress, have been slow to focus on the 2020 race.
As the names of the Wing Ding's speakers were read, the applause was mild - until the audience heard "Michael Avenatti."
Onstage, in front of a massive American flag, Avenatti sounded every bit a candidate. He described how Trump's "disastrous approach to trade" had hurt Iowa and said that his deregulation agenda would lead to "slimy rivers and filthy air."
He argued that Democrats could win back Trump voters, because "decent people get conned all the time."
He also informed the audience that he was born "not far from here, in Missouri," and lived the American Dream, the one that Democrats could offer voters if they picked the right candidate.
"In the eternal battle of David versus Goliath, we are the party of Davids," he said. "And when you are the party of Davids, you cannot afford to show up without a slingshot."
