It's a pretty little mess. Despite being warned by the chairman of the FEC that he could not withdraw from the primary public funding system without the FEC's say-so, McCain, claiming to have withdrawn, has continued to spend away, by now far exceeding the spending cap. And the FEC remains powerless to act. (Here's our rundown on the whole thing.)

Today, the Democratic National Committee filed suit in federal court, seeking to force the FEC to action. The DNC filed a complaint with the FEC back in February, but since the FEC does not have enough commissioners to officially open an investigation, nothing has happened. The suit asks that the judge order the FEC to act, and if it doesn't, clear the way for the matter to be resolved in court. The soonest that could happen, DNC lawyers say, is June.

Here's a copy of the suit filed today.