Third party groups supporting Hillary plunked down an astonishing sum of nearly $300,000 in political spending in one day yesterday, a cash outlay that will almost all fund mailings and phone-bank calls.

FEC filings show that the pro-choice group Emily's List shelled out nearly $190,000 yesterday for mailers and phone banks, while the American Federation of Teachers spent nearly $95,000 yesterday, all on direct mail. The filings show the dates of the expenditures, but not necessarily when the mailings will be sent or the calls will be made.

The nearly $300,000 is a big one-day buy that will almost certainly unleash a wave of mailings in the next few days, most likely in Iowa and perhaps in New Hampshire. At least one third-party mailing has already caused controversy in the race: Yesterday John Edwards criticized the Hillary campaign over a mailer sent out by a pro-Hillary labor union attacking Barack Obama's health care plan, saying that the mailing's inclusion of an Edwards quote was designed to suggest that Edwards was behind it.

As the race nears the voting, we'll see more big one-day money drops like these -- and we'll be cataloging them all here at TPM Election Central.