Ehrlich, who had just about $140,000 in the bank in January, months before he made official his new bid for his old office, has said he'd like to hit $3 million by the end of today.

"We are on the cusp of sending a strong message to the incumbents in Annapolis, but I need your help to cross the finish line," Ehrlich said in an email to supporters. "We have one goal for tomorrow's deadline: report $3 million in contributions since March."

Meanwhile, O'Malley, who had about $5.7 million, says he's raised more than $130,000 in the past 24 hours alone.

"We're all blown away by the support you have given the Governor in the last few days," O'Malley finance director Adam Goers said in an email to supporters. "We set an aggressive goal of $100,000 raised online before tonight's filing deadline, and I'm proud to say that, with your support, we topped that goal before noon today!"

O'Malley's aides have characterized Ehrlich's goal to hit $3 million as a sign of weakening support. They point to an interview in March where Ehrlich aides said they had a goal of raising $1 million in the month of March.

But Ehrlich and his aides have long hinted that they're not planning a dollar-for-dollar battle with O'Malley, whom they said has had four years to raise "piles" of money.

Richard E. Hug, Ehrlich's longtime fund-raiser, said in March that the race will be "about the message and the messenger," rather than the money.

Ehrlich spokesman Henry Fawell said Tuesday that the campaign had devised a "sensible fundraising plan for an out-of-power challenger, and I'm pleased to say that we're very much on target."

The State Board of Elections will make the totals public next week. We'll be able to see exactly how much each candidate -- not just Ehrlich and O'Malley, but everyone running for the state legislature, federal posts and local offices -- has raised. Equally important, we'll know how they're spending their money.

With midnight looming, the candidates are hoping to turn their pleas into cash.