Here are the biggest endorsements all the 2020 Democratic presidential candidates have received so far

• The first caucuses and primaries of the 2020 presidential election are almost 11 months away, and the 15 candidates currently vying for the Democratic nomination are scrambling to shore up support among the rest of their party.

• While candidates with the most endorsements before the Iowa caucuses have historically ended up clinching the nomination, endorsements haven't been as predictive in ultra-crowded primaries with no clear front-runner, like the 2020 Democratic primary. 

• Here's our tracker of which 2020 Democrats have the most major endorsements - from statewide officials, federal officials, and prominent celebrities. 

The first caucuses and primaries of the 2020 presidential election are almost 11 months away, and the 15 currently-declared candidates currently vying for the Democratic nomination are scrambling to shore up support among the rest of their party.

As FiveThirtyEight's Nate Silver recently reported, the hypothesis put forth by the book "The Party Decides" is that endorsements have been a helpful predictor for who will prevail in presidential primaries. The somewhat controversial theory posits that in primaries, voters often take their signal of who to vote for partially from the endorsements of prominent party elites.  

Read more: Beto O'Rourke has already secured multiple endorsements from prominent moderate Democrats who don't live in his home state

In the 16 Democratic and Republican presidential primaries between 1972 to 2016, the candidate with the most endorsements before the Iowa caucuses ended up clinching the nomination in 9 out of the 11 contests that had a clear endorsement leader, according to data compiled by FiveThirtyEight.

"The party usually does get its way," Silver wrote. "But it also usually agrees with voters in the first place - or at least it can live with their choices - and it's not so clear what happens in the event of a disagreement." 

Party support has been a less predictive barometer of success in ultra-crowded fields with no clear front-runner, like the 2016 Republican primary, and now, the 2020 Democratic contest.

We've narrowed down every candidate's full list of backers to their most prominent endorsements from statewide politicians, federal representatives, and celebrities, and will be tracking them throughout the primary to see how much the "party decides" model holds this time around:

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