Jim Messina, campaign manager for President Obama’s reelection campaign, said in a blog post and e-mail to supporters that they will support Priorities USA, the SuperPAC set up by two former White House aides.

Even with a $2 million contribution from Jeffrey Katzenberg and other support from donors such as Steven Spielberg and J.J. Abrams, Priorities has fallen way behind GOP SuperPACs in fundraising. Messina said that the reason the decision was made to support Priorities, even though Obama has decried the Supreme Court’s Citizen’s United decision, was to “neutralize the avalanche of special interest spending to defeat President Obama.”

“The campaign has decided to do what we can, consistent with the law, to support Priorities USA in its effort to counter the weight of the GOP Super PACs,” Messina wrote. “We will do so only in the knowledge and with the expectation that all of its donations will be fully disclosed as required by law to the Federal Election Commission.”

Although the campaign cannot coordinate with Priorities, an independent expenditure committee, it does have some leeway in the delicate interpretation of the law. It means that donors that have maxed out to the official campaign can be lured to similar types of fundraisers where they can write checks for unlimited amounts. It is also a nod to bundlers that it is OK for them to raise for Priorities. Obama’s reelection campaign can collect a maximum of $5,000 per person for the entire cycle.

“What this change means practically: Senior campaign officials as well as some White House and Cabinet officials will attend and speak at Priorities USA fundraising events,” Messina wrote. “While campaign officials may be appearing at events to amplify our message, these folks won’t be soliciting contributions for Priorities USA. I should also note that the President, Vice President, and First Lady will not be a part of this effort; their political activity will remain focused on the President’s campaign.”

Priorities was started last year by Bill Burton and Sean Sweeney.

Messina’s blog post is here.