The real action of the 2020 Democratic presidential campaign has gotten off to a slightly slower start than most insiders expected—the political world was full of speculation that someone might announce by Thanksgiving, or at least by the week after. Neither happened.

That’s left room for some of the lesser-known hopefuls to try to grab some of the spotlight before the bigger stars show up.

Their first big stop in Iowa, home of the caucuses: the Progress Iowa annual holiday party, coming up December 20 in downtown Des Moines. Headlining it this year will be South Bend, Indiana, Mayor Pete Buttigieg, Oregon Senator Jeff Merkley, Representative Eric Swalwell of California, and Andrew Yang, a businessman.

Read: A lot of people want Bernie Sanders to run in 2020.

Organizers invited several better-known candidates, but were told that they weren’t ready to make the leap of going to Iowa and push the speculation into overdrive.

It won’t be the first time in Iowa for any of these prospective candidates, and it’s looking like it won’t be the last, with the Democratic field seeming to be in the accordion phase of politician after politician looking up and saying, “Hey, why not me?”

But the liberal political-activist group has developed a knack in its short, six-year history for being an early stop for mostly unknown Democrats who’ve then splashed into the presidential field: Bernie Sanders was the main guest in 2014 ahead of his last presidential run, and Jason Kander was the main guest in 2016, on the way from transforming from a losing Missouri Senate candidate into a nationally known Democrat who was, at one point, expected to make a presidential run of his own for 2020. And that’s made it a key stop for presidential speculation: Last year, New York City Mayor Bill de Blasio used his own appearance at the event to stir the pot that he might be making yet another play for national politics—though this attempt, like his previous ones, never quite materialized.