Priorities USA Action, the super PAC backing President Barack Obama's re-election effort, had its best month of fundraising in August, collecting $10.1 million. That's more than twice as much as the group has raised in any month but one, and a third of the total amount it has brought in since it was started by two former Obama aides last year.
Priorities spent $9.5 million, and had $4.8 million in the bank at the end of August.
The super PAC supporting Romney, Restore Our Future, pulled in just over $7 million last month. But American Crossroads, the Karl Rove-connected super PAC that has spent millions supporting Romney as well, raised $9.4 million while spending $6.9 million.
That leaves American Crossroads with a whopping $32 million still in the bank, which it can let loose as an an enormous water balloon of negative advertising in the closing weeks of the campaign.