Former Vice President Joe Biden has less money in his campaign account heading into the early nominating contests than his top 2020 rivals.

Federal Election Commission (FEC) filings released by Biden’s campaign late Friday indicate he only had $8.9 million on hand at the start of this year despite raising a whopping $23.2 million in the last three months of 2019. The former vice president’s previous fundraising troubles and his penchant for heavy spending, including private air travel and other high-end accommodations, seem to be the cause of his current cash crunch.

Between October 1 and December 31, 2019 — the end of the fourth quarter FEC deadline — Biden’s campaign spent nearly $23.3 million, a little more than it raised. The former vice president kept spending money even as his campaign was already behind financially. Biden started the fourth quarter with nearly $9 million on hand, the lowest of any top-tier contender. Without proper reserves, Biden was continuously being forced to use incoming contributions to pay for present expenditures throughout the fourth quarter.

As such, Biden’s current campaign coffers pale in comparison to rival Democrats. In the fourth quarter, Sen. Bernie Sanders (I-VT) raised more than $34.5 million but also spent more than $50 million in the same period. The self-described Democratic socialist’s high burn rate was offset by large fundraising hauls from previous quarters.

Since jumping into the race, Sanders has raised more than $108 million for his candidacy, the majority of which has come from small-dollar donors. With that much money, Sanders was able to spend heavily and still start 2020 with nearly $18.2 million in the bank. The cash advantage will help fortify the senator’s position in Iowa and New Hampshire, where he leads in most polls.

Similarly, former South Bend Mayor Pete Buttigieg benefited from his previous fundraising prowess despite spending more than he raised. During the fourth quarter, Buttigieg raised more than $25.1 million, while spending more than $34 million over the same period. Buttigieg ended the year with more than $14.5 million on hand, a result of raising more than $76.7 million overall since launching his campaign.

Sen. Elizabeth Warren (D-MA), on the other hand, raised only $21.6 million during the fourth quarter, slightly less than Biden. The Massachusetts Democrat, however, spent $33.6 million, ensuring her cash on hand at the end of December was $13.7 million. Warren was boosted by the fact that she started the fourth quarter with nearly $25 million in her campaign account.

The cash disparity between the three candidates has the possibility to upend the race for the Democrat nomination. Even though the Iowa Caucuses are only days away, the contest will remain competitive at least until Super Tuesday when a substantial portion of the delegates are up for grabs. A number of the states holding their primary that day — including Texas, California, North Carolina, Virginia, and Massachusetts — have expansive and costly media markets that are likely to become a drain on candidate resources.

Complicating matters is that the Democrat field, which is the largest in a generation, is not inclined to shrink until at least after Super Tuesday, potentially prolonging the race and tying up new avenues for fundraising.

All of that ensures the money candidates already have in the bank will be vital to surviving the next leg of the 2020 race.

Biden, though constrained by his meager campaign coffers, does have the luxury of being one of the only Democrats with a Super PAC working on his behalf. The group, called Unite the Country, has already spent more than $4.3 million in hopes of creating a last-minute surge behind the former vice president in Iowa.

In fact, Unite the Country has already surpassed what Biden’s campaign is on course to spend in first caucus state — and has provided no indication its efforts will stop anytime soon.