Some of the people who likely know the most about the role politics has played in the Bush Justice Department have defied Congressional subpoenas to testify. Joshua Bolten, the White House chief of staff, and Harriet Miers, the former White House counsel, contend that they are protected from testifying by executive privilege. That is not enough. They have a legal obligation to appear before Congress and plead that privilege to specific questions.

The House Judiciary Committee voted in July to hold Mr. Bolten and Ms. Miers in contempt. The House’s Democratic leadership has been trying to figure out the pros and cons ever since. The public needs to hear the testimony of these officials (along with Karl Rove, who is also refusing to appear), and the full House should vote as quickly as possible to hold them in contempt.

The House should also approve a resolution authorizing the Judiciary Committee to go to court to enforce the contempt citations if the current attorney general, Michael Mukasey, as expected, refuses to do so.

The stakes are high. There are people in jail today, including a former governor of Alabama, who have raised credible charges that they were put there for political reasons. Congress’s constitutionally guaranteed powers are also at risk. If Congress fails to enforce its own subpoenas, it would effectively be ceding its subpoena power. It would also be giving its tacit consent to the dangerous idea of an imperial president  above the law and beyond the reach of checks and balances.

The founders did not want that when they wrote the Constitution, and the voters who elected this Congress do not want it today.