Over the past 18 months, a core group of Democrats and others from the left has steadfastly maintained that President Bush and Vice President Cheney should be impeached. Mainstream Democrats in Congress are sympathetic to their arguments, but most have bowed to the political reality that impeachment proceedings would gridlock the federal government in the last year of the Bush administration, distract lawmakers from resolving problems that affect the daily lives of Americans, and possibly trigger an endless cycle of reprisal impeachment attempts for future administrations.

There is another angle on this difficult question, raised by Rep. Michael Michaud in a Dec. 21 letter to Rep. John Conyers, chairman of the House Judiciary Committee. “There is no doubt that at the very least this Administration has dangerously expanded the scope of executive authority and flaunted the constitutionally defined separation of powers,” Rep. Michaud wrote.

The letter urges Rep. Conyers to schedule impeachment hearings on Mr. Cheney, though not on the president’s conduct. Those supporting impeachment argue Cheney in his role in the administration has repeatedly violated the Constitution on matters such as warrantless telephone eavesdropping, deliberately misled Congress and the American people about the threat posed by Iraq and Iran, revealed the name of a CIA agent, and ordered the abuse of prisoners in violation of international treaties.

The specific alleged abuses of power will, for the most part, fade away when the Bush-Cheney administration leaves Washington. But the “dangerously expanded” powers of the executive branch cited by Rep. Michaud could remain in place. Those powers will be inherited regardless of which party takes the White House, and while Democrats may relish the opportunities that come with an expanded presidency, ultimately, such an imbalance in the government is unhealthy and will increase the chance of future abuses.

Mr. Bush’s interpretation of executive powers has led critics to dub his tenure the “imperial presidency.” Rep. Michaud correctly notes in his call for hearings on impeachment of Mr. Cheney that: “Expansions and potential abuses of power by this administration become precedents for future ones, which lead to further erosions of our constitutional rights.”

Rep. Michaud had given the impeachment matter long and careful thought, his press secretary Monica Castellanos reported, before calling for the hearings. The congressman has not prejudged the outcome of the hearings and possible investigation, she said, but he strongly believes those steps are essential in restoring Americans’ trust in their government.

It is a big step for Congress to take, especially in a politically charged presidential election year. But if it is possible, a dispassionate examination of the manner in which Mr. Cheney and this administration have stretched the executive branch to the point of distorting its constitutional definition would be enlightening, and could help rebalance the powers of the federal government.