Democratic Party insiders now reportedly believe that democratic socialist Sen. Bernie Sanders (I-VT) could win the 2020 presidential nomination, despite having written him off months before.

Politico reported Thursday that the stumbles of former Vice President Joe Biden and the recent setbacks suffered by Sen. Elizabeth Warren (D-MA) have given the 78-year-old Sanders, who recently suffered a heart attack, the inside track on the party’s primary contest.

As Politico noted:

For months the Vermont senator was written off by Democratic Party insiders as a candidate with a committed but ultimately narrow base who was too far left to win the primary. Elizabeth Warren had skyrocketed in the polls and seemed to be leaving him behind in the race to be progressive voters’ standard-bearer in 2020. But in the past few weeks, something has changed. In private conversations and on social media, Democratic officials, political operatives and pundits are reconsidering Sanders’ chances. … Democratic insiders said that they are rethinking Sanders’ bid for a few reasons: First, Warren has recently fallen in national and early-state surveys. Another factor, they said, is that he has withstood the ups and downs of the primary, including his own heart attack. At the same time, other candidates with once-high expectations, such as Kamala Harris, Cory Booker and Beto O’Rourke, have dropped out or languished in single digits in the polls.

As Breitbart News has reported, Sanders has a strong chance to repeat his 2016 victory in the New Hampshire primary on Feb. 11, though he is not expected to win in Iowa, Nevada, or South Carolina. He could also do very well on Super Tuesday, March 3 — especially in California, the biggest source of delegates to the party convention, where he is campaigning hard and where he consistently draws massive crowds and glowing celebrity endorsements.

Sanders has a loyal following that does not seem to grow, but does not seem to shrink, either. The left-wing grassroots of the party, energized by new voices such as Rep. Alexandria Ocasio-Cortez (D-NY), remains enthusiastic about his candidacy, seeing him as the candidate the party should have chosen in 2016. Some of his supporters are openly contemptuous of other left-wing alternatives, like Warren, whom they accuse of stealing his ideas.

Warren has also struggled to defend her version of Sanders’s “Medicare for All” plan. Initially, she dodged questions about whether it would raise taxes on the middle class (and she still maintains that it would not, though few believe her). Her plans for a wealth tax have also drawn criticism.

Biden has appeared unsteady or distracted at times, and his past conflict of interest in Ukraine has come into focus with the impeachment inquiry into President Donald Trump.

No other candidate outside the top three is a serious threat to win the nomination at the moment. South Bend, Indiana, Mayor Pete Buttigieg is competing for the top spot in Iowa but has little nationwide support.

Sanders pushed for a change to the party’s superdelegate rules, which could help him survive on the first ballot at the party convention in Milwaukee, Wisconsin, next summer.

The superdelegates — party leaders and elected officials — can vote in later rounds, which means that Sanders would need their support to prevail at a “brokered” convention.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. He earned an A.B. in Social Studies and Environmental Science and Public Policy from Harvard College, and a J.D. from Harvard Law School. He is a winner of the 2018 Robert Novak Journalism Alumni Fellowship. He is also the co-author of How Trump Won: The Inside Story of a Revolution, which is available from Regnery. Follow him on Twitter at @joelpollak.