By David Siders, Politico–

First Michael Avenatti imploded, announcing he will not run for president in 2020. Then came Deval Patrick, who told allies that he, too, is out, despite spending the fall campaigning with candidates across the country. Joe Biden, meanwhile, was declaring himself “the most qualified person in the country to be president,” edging closer to a full-on campaign.

In just one convulsive 24-hour period, Democrats got a glimpse of the primary election to come, a precursor to a year of volatility in the party’s historic, sprawling 2020 presidential field.

Yet the departure of two candidates — and another seeming to suggest his intention to run — failed to provide any more clarity or definition to the field on the eve of a period in which many candidates have said they will announce their intentions.

“This is like rats in a Skinner maze,” said Hank Sheinkopf, a longtime Democratic strategist based in New York. “Who gets to the end is a function of who has the best luck, who has the most money and who doesn’t anger the media.”

The Democratic primary field is shaping up to be so large and fluid that the loss of one former governor, Patrick, barely makes a dent — there are still six other current or former governors in the mix. Avenatti‘s exit Tuesday removes an outsider and a ferocious Trump critic, but that’s also a lane that few expect will be unoccupied when the field is set. As for Biden, the former vice president and early frontrunner in national polls, his tease generated heat but without providing much light on his thinking about entering the race.

Over the next six weeks, said Bill Burton, a Democratic strategist and veteran of the Obama White House, “I think that the number of people who we think will run for president will contract … There’s already 20 or 30 people in circulation who are considering it. Not all of them are going to run.”

But while potential contenders begin to drop off, others are taking their place. In the latest expression of Democrats’ post-midterm euphoria, Colorado Public Radio reported this week that Sen. Michael Bennet (D-Colo.) is “seriously thinking” about a 2020 campaign. Sen. Bob Casey (D-Pa.), who didn’t register on the 2020 radar until his decisive reelection win in November, said recently that he is “open to all possibilities.”

“There’s so many names now … You wonder who’s really serious and who’s doing it just for getting a higher bump in exposure for something down the road, be it a TV host, a radio syndication, a book deal,” said Matt Barron, a Massachusetts-based political consultant who worked on the presidential campaigns of Barack Obama and John Kerry.

Barron said the breadth of the field — and tumult within it — presents an opportunity to lower-profile candidates, potentially explaining why Bennet, Casey or any number of Democrats might not rule out a campaign.

With a larger field, he said, “If someone can win with a smaller piece of the pie, then mathematically it seems to be easier … In a large field, they just need a smaller slice.”

Most top-tier candidates are not expected to announce their candidacies until early 2019, allowing them to take advantage of a full fundraising quarter before reporting their initial fundraising numbers. But as Democrats scramble to secure staffers in key primary states, some candidates may be forced to announce early.

“I think there’s this big game of chicken going on, and campaigns are trying to get commitments from staff, and I think [staffers] are reluctant to dive in until they know what’s really going on with a candidate,” said Jeff Link, a Democratic strategist in Iowa. “So, if these campaigns are nervous about locking staff in, that may push the timetable up for them.”

He said, “Having 30 candidates is probably not sustainable, but I think we’ll have more than 15.”

Avenatti and Patrick, like the potential rivals they left behind, had been laying groundwork for 2020 for months, and the transition to a more overt campaign began immediately after the midterm elections. But the burst in activity this week — squarely between the Thanksgiving and Christmas holidays — still took some observers by surprise. In most elections, one potential candidate, former San Antonio Mayor Julián Castro, told an audience in San Diego recently, campaigns settle into a relative lull over the holidays, before picking up in January.

But the events this week — and the widespread attention given to even minor progressions in the campaign — reflected the swiftness with which Democrats are moving toward 2020, less than a month after the midterm elections.

“It’s going to be such a free-for-all,” said Matt Bennett of the center-left group Third Way, lamenting the likelihood that an immediate shift to 2020 will overshadow Democrats arriving in Washington with a majority in the House.

“What I hope, and I think the party should hope, is that [House Democrats] get some moments in the sun before they’re blotted out by the 2020ers,” Bennett said. “I do hope that they’re given a little bit of a chance to articulate a vision for the country as a new Congress gets underway, before the ‘he said, she said, he said, he said, he said, she said,’ starts.”

Yet he predicted there’s no stopping the candidate tsunami of 2020: “It’ll be like, ‘Breaking from Des Moines: Kamala Harris sneezed three times’ … And meanwhile we’ve got people toiling away to change the direction of the country. It’s just hard to get attention.”

Biden made his remarks about being the “most qualified” during an appearance Monday at the University of Montana in Missoula. Antjuan Seawright, a South Carolina-based Democratic strategist who worked for Hillary Clinton’s campaign in 2016, called Biden’s pronouncement an exercise in “ramp up to ramp down.”

“Biden is ramping up to try to clear the field, so if he gets in he won’t have a tough run,” Seawright said.

Over the next six weeks, he said, many Democrats who are interested in running for president will likely abandon their efforts after determining they are not competitive. But even then, they will contribute to the ongoing frenzy of the 2020 campaign.

In the case of Patrick, who appeared at an event that Seawright helped to organize in South Carolina recently, the now former presidential prospect will immediately join another sweepstakes instead.

Seawright said, “He will be on most, if not everyone’s, short and long list for VP.”