Sen. Bernie Sanders had the most cash to deploy in the 2020 Democratic presidential primary heading into the final three months of the year, as former Vice President Joe Biden struggled to keep pace with his top rivals for the nomination.The Vermont independent’s campaign had $33.7 million on hand at the end of September, easily the most in the 19-person field trying to challenge President Donald Trump next year, according to Federal Election Commission records filed Tuesday. Sen. Elizabeth Warren, D-Mass., and South Bend, Indiana, Mayor Pete Buttigieg followed with $25.7 million and $23.4 million in the bank, respectively.Biden, whose position as the race’s clear front-runner has eroded, fell far behind his top rivals with only about $9 million on hand at the end of the third quarter. His campaign raised less in the three-month stretch than those of his rivals: he took in $15.7 million in individual contributions, versus $25.3 million, $24.6 million and $19.1 million for Sanders, Warren and Buttigieg, respectively.President Donald Trump looms over them all in the 2020 money race. Powered by a joint fundraising operation with the Republican Party and facing little competition for donors within the GOP, the president’s campaign ended September with $83.2 million in the bank.Trump boasts a massive cash edge over all of his potential rivals that will likely only grow in the coming months as Democrats jockey for position ahead of the first primary nominating contests in February.At least 11 of the 19 Democratic campaigns burned through more money than they raised in the third quarter. They include Biden, Sens. Kamala Harris, D-Calif., Cory Booker, D-N.J., Amy Klobuchar, D-Minn., and former Rep. Beto O’Rourke.Billionaire activist Tom Steyer’s campaign spent about $47 million in the third quarter, more than doubling Sanders, the next biggest spender with $21.6 million. Steyer, a former hedge fund manager, piled $47.6 million of his own money into the campaign.— Charts by CNBC’s Nate Rattner.Subscribe to CNBC on YouTube.