WASHINGTON (AP) — Many Democratic presidential candidates launched their campaigns last year with bold pledges to reject help from super PACs and dark money groups.

But as the realities of a tough primary fight sink in, those promises are fading away.

Elizabeth Warren, one of the fiercest critics of money in politics, was the latest White House hopeful this week to accept help from a big money organization that can raise and spend unlimited amounts on behalf of political candidates.

Former Vice President Joe Biden, Minnesota Sen. Amy Klobuchar and Bernie Sanders have done much the same.

The Democratic battle to take on President Donald Trump is entering a critical new phase as more than a dozen states vote within the next couple of weeks with about one third of the delegates needed to win the nomination at stake.

Campaign finance disclosures made to the Federal Election Commission on Thursday offered the clearest look yet at who will have the resources to forge on deep into the calendar and who will be forced to soon reckon with the sustainability of their candidacy.

The disclosures include campaign spending and fundraising details for the month of January and laid bare the stark financial choices ahead for those other than former New York Mayor Michael Bloomberg and Sanders.

Bloomberg, a billionaire, has plunged over $400 million into his campaign, while Sanders is propelled by an army of contributors whose renewable stream of small online contributions helped him amass $25 million in January alone.

“Our campaign has built a nationwide organization that is engaging voters daily,” said Bloomberg campaign manager Kevin Sheekey. “With over 2,400 staff across 43 states today, Mike is the only candidate with the record and resources to build the national infrastructure Democrats need to beat Donald Trump.”