Sen.-elect Elizabeth WarrenElizabeth Ann WarrenOvernight Regulation: Net neutrality supporters predict tough court battle | Watchdog to investigate EPA chief's meeting with industry group | Ex-Volkswagen exec gets 7 years for emissions cheating Overnight Tech: Net neutrality supporters predict tough court fight | Warren backs bid to block AT&T, Time Warner merger | NC county refuses to pay ransom to hackers Avalanche of Democratic senators say Franken should resign MORE (D-Mass.), who defeated Sen. Scott Brown (R-Mass.) in one of the most closely-watched and expensive races in the nation, has asked for help to retire her $400,000 in campaign debt.

Warren broke Massachusetts fundraising records with her $42 million haul, but she said in an email to supporters that she incurred some debt because of an "embarrassment of riches," in the form of the unexpected levels of support she says she received.

"When my campaign team planned our final budget, we knew our Get Out the Vote push was going to be BIG. But it was far bigger than anyone ever expected," she writes in the email.

"This extraordinary effort was wonderful and it's how we won, but it created some planning challenges," Warren adds.

Warren said that the high number of volunteers and voters asking for help getting to the polls meant unexpected expenditures in the form of "last-minute coffee and pizza" and vans to drive people to the polls.

A campaign source said the $400,000 was less than 1 percent of what she raised overall.

Warren's not the only candidate looking to pay down their campaign debt; both Sen.-elect Ted CruzRafael (Ted) Edward CruzDebbie Wasserman Schultz marks 10 years as breast cancer survivor Foreign agent registration is no magical shield against Russian propaganda Let Trump be Trump and he'll sail through 2020 MORE (R-Texas) and Rep.-elect Tulsi GabbardTulsi GabbardTulsi Gabbard is no snowflake Texas shooting puts scrutiny on military's criminal reporting system Overnight Defense: Details on 2 billion compromise defense bill | Space Corps dropped from bill | Mattis requests probe into Texas shooter's records MORE (D-Hawaii) have thrown post-election fundraisers to help retire their debt, among others.

Warren, who sources say has landed a coveted spot on the Senate Banking Committee and has already come out as an outspoken proponent of filibuster reform, acknowledged in the email that some supporters may be fatigued from the continued pleas for cash and said that she'd rather be focusing on her job in the Senate.

"I know this was the most expensive Senate race in the country. And I know that we've sent you a bazillion emails asking for money over the past year. I'm sure you expected them to all end once the votes were counted — and yes, that's what I thought too. Right now, I'd rather be writing about filibuster reform and banking regulation," she said.

But the request came anyway: "Can you help one more time to finish 2012 strong?"

--This post has been updated to reflect the amount of debt Warren incurred.