The Senate is required to provide advice and consent to the President on his choice of cabinet officers. Usually all the Senate provides is consent in that it approves the individuals the President puts forward. But the Senate not only has a right, but a duty to advise the President on who he chooses for posts they approve.
The Senate Democrats should caucus and advise the president to appoint David Iglesias as Attorney General. He has the conservative credentials to be acceptable to the Republicans. At the same time, he has the integrity to be acceptable to the Democrats.
At the same time, while Iglesias is just a suggestion, the Democratic Senators should be very clear that they will not accept any candidate that is not as good as or superior to Iglesias. The Senate has the power to insist that the next Attorney General be a person of unquestionable integrity.
The beauty of this approach is by putting up someone who is clearly a staunch Republican and supremely well qualified, they are accepting Bush's right to appoint someone who is a conservative Republican. But by suggesting an individual rather than a generic "someone of integrity", any other candidate can be measured specifically against Iglesias.
And this will stop us from accepting someone less. The Department of Justice needs a leader who will unquestionably clean up the political cesspool Gonzales created there. Acceptable is not enough, we need superb.