A Democratic-aligned super PAC run by two former Obama White House aides has begun reserving $30 million worth of television ad time in six swing states as it seeks to combat the heavy spending by conservative outside groups.

U.S. President Barack Obama shakes hands before he speaks at a campaign event at Mansfield Central Park in Mansfield, Ohio August 1, 2012. REUTERS/Larry Downing (UNITED STATES - Tags: POLITICS)

Priorities USA Action, which is run by former White House aides Bill Burton and Sean Sweeney, has raised $16 million this year — as of the end of June — and $21 million since the start of 2011. It recently received a $1 million donation from actor Morgan Freeman. The group says it has another $20 million in commitments.

Those fundraising figures are dwarfed by the activity of Republican super PACs and other conservative-aligned outside groups led by American Crossroads and Crossroads GPS, which has pledged to spend $300 million on the 2012 election.

As of the third week in July, Republican outside groups had spent $144 million on swing state television advertising while Democratic groups — led by Priorities USA Action — had spent just over $20 million.

The dual-headed Crossroads group — one arm is a super PAC, the other a not-for-profit — had spent upward of $90 million on ads by itself by that time.