Make no mistake: Barack Obama is not hard up for cash. His $36.1 million cash on hand is a huge amount, yet he trails Sen. Hillary Clinton by $2.1 million.

In his latest fundraising pitch, Obama uses that minor disparity to urge his supporters to help him catch up. "The situation here is simple. We are $2.1 million behind. We must close that gap right now. I need you to make a donation," Obama writes in a fundraising email. "Hillary Clinton aggressively seeks money from Washington lobbyists and special interest PACs. She's even said that these lobbyists represent real Americans. She's wrong."

The admission and the hit on Clinton, which plays into Obama's perceived strength as a straight-talking outsider, are both smart moves. "Washington lobbyists have chosen their candidate (ed. note: Which candidate, Mr. Obama?) and are determined to provide her (ed. note: Oh...) with an overwhelming advantage. But you can even up this contest."

No pundit or prognosticator can seriously believe that the difference between $38 million and $36 million is the difference between a win and a loss. But by sending subtle hints of urgency, we're betting Obama finds this email to be one of his most successful during the campaign.

Mark Halperin, who has a copy of the email, thinks this is the opening salvo of Obama's new phase of taking on Clinton more directly. The attack is certainly direct, and could signal the beginning of the bloody phase of the primary.