William Belknap, Ulysses S. Grant’s disgraced secretary of war, is experiencing a revival. Impeached in 1876 for taking bribes, he has become the inspiration for a movement to remove Attorney General Alberto Gonzales from office. Impeachment is usually thought of as limited to presidents, but the Constitution not only allows the impeachment of Cabinet members, in Belknap’s case, it was actually done.

Impeaching Mr. Gonzales has moved beyond the hypothetical, now that Jay Inslee, Democrat of Washington, and five other prosecutors-turned-representatives have introduced a resolution to conduct an impeachment inquiry. Congress is wary, and not only because of post-Clinton impeachment hangover. The grounds set out in the Constitution are vague, and the Democrats do not want to be seen as overreaching.

Members of Congress should keep in mind, however, that the founders gave them the impeachment power for a reason — and Mr. Gonzales’s malfeasance is just the sort they were worried about.

The Constitution provides for impeachment for “treason, bribery, or other high crimes and misdemeanors.” Not a clear formula, but it wasn’t meant to be. Impeachment, Alexander Hamilton explained in Federalist 65, cannot be “tied down” by “strict rules, either in the delineation of the offense” by the House, or “in the construction of it” by the Senate.