Democrats should initiate a resolution stating that the Justice Dept. shouldn't be allowed to claim executive privilege over the Attorneygate subpoenas, because the ones making that judgment are primary subjects in the legal dispute over the fired attorneys.
Further, Democrats should press for another resolution directing the Senate Legal Counsel to bring a civil action to enforce the subpoena, to sue for enforcement. In that proceeding, the conflicts of interest could be highlighted and addressed. Congress could even press for that outside judgment right away, before any hearing.
Up until now, all of the action has been in committee. It's getting to the point where these subpoena matters should be brought to the floor of both houses for resolution.
Here's an instance where Congress successfully pressed their case for subpoenaed documents withheld under claims of privilege:
Duke Law Journal on the republicans' subpoena of Whitewater notes . . .In 1995, the Special Senate Committee to Investigate Whitewater Development Corporation and Related Matters (the Senate Whitewater Committee) issued a subpoena for certain documents. The White House announced that it would withhold material about a November 5, 1993, meeting involving senior presidential aides and private lawyers, on the ground that the documents were protected by the lawyer-client privilege and executive privilege. William Kennedy, who at the time was an associate White House counsel, took extensive notes at the meeting. President Clinton said that he believed "the president ought to have a right to have a confidential conversation with his minister, his doctor, his lawyer." That argument would apply if a president met with his private lawyer, but the issue was complicated by the presence of government lawyers at the meeting.
Within a few days, the White House offered to turn over the Kennedy notes if the committee agreed that the meeting was privileged. The committee refused because it learned of other meetings attended by White House officials and private attorneys. Unable to reach an acceptable compromise, the committee voted to send the issue to the Senate floor and from there to federal district court.
On December 20, 1995, the Senate began consideration of a resolution directing the Senate Legal Counsel to bring a civil action to enforce the subpoena. The resolution invoked a special statute regarding the authority of the Senate Legal Counsel to sue for subpoena enforcement orders. In a letter on that same day to the committee, White House Special Counsel Jane Sherburne described various options, stating: "We have said all along that we are prepared to make the notes public."The resolution passed the Senate by a vote of fifty-one to forty-five. On the following day, the White House agreed to give the notes to the Senate Whitewater Committee.http://www.law.duke.edu/shell/cite.pl?52+Duke+L.+J.+323