Joe Biden's entrance into the 2020 presidential race is a seismic shift, here are the rival contenders that are in the most trouble

• According to recent INSIDER polling conducted over the course of the spring, 63% of Democrats would be satisfied with former Vice President Joe Biden as nominee.
• Biden is the frontrunner but overlaps considerably with the competition when it comes to supporters.
• Kirsten Gillibrand, Amy Klobuchar, Beto O'Rourke and Cory Booker all are drawing on a base of support that also tends to really like Biden. Biden entering is bad for them.
• Kamala Harris, Elizabeth Warren and Bernie Sanders also overlap with Biden, but are better positioned to survive his entrance and potentially capitalize on other candidacies throwing in the towel.
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Joe Biden, a Democratic party fixture for a generation who spent eight years as the vice president to one of the Democratic Party's most enduring popular figures, has entered the presidential race.

Biden's potential entry has hovered over the contest so far and led to increased uncertainty in the early part of a Democratic primary already defined by uncertainty. The reality is that it's far too early in the cycle to draw sweeping conclusions about the presidential possibilities of any one candidate.

What we do know, though, is Biden formally entering the race constitutes a fairly seismic shift.

Read more: Former Vice President Joe Biden is running for president in 2020, warning that another term of Trump would tarnish America's soul forever

INSIDER has been conducting a recurring SurveyMonkey Audience poll that tries to find overlaps in each candidate's constituencies. We're concerned mainly with people who say they're likely going to participate in the Democratic party primary and who said they are registered to vote. We ask who in the race they're aware of and who they'd be satisfied and unsatisfied with as nominee. From there, we can interpret overlapping constituencies and what percentage of a given candidate's pool of support is also being targeted by another contender.

Read more about how the INSIDER 2020 Democratic primary tracker works

Biden is the most popular candidate in the field and conceivably draws support from every candidate's base. But based on the past six editions of this poll, conducted Feb. 15 through Apr. 18, here's who's really in trouble and who could be just fine.