Senate to investigate House??

Liberal Senators are asking that the Justice Department launch an investigation on the legality of an earmark placed on a 2005 highway funding bill. The initial earmark was approved for $10million to make improvements on Florida's I-75, but was altered just before the bill reached the President for signing. A problem arises with how the Senate can go about with the investigation. Conservatives say that the Justice Department does not have to launch an investigation if directed by the Senate, and they propose that a Committee to be formed for the investigation. Liberals say that it is unconstitutional for the Senate to investigate the House.
Little will probably occur in response to this finding. It sounds like to me that Senators are riding the wave of earmark abuse. If they show they are trying to limit pork barrel spending, maybe it will give them a boost for November elections.