There is no shortage of paeans to the Constitution of the United States in senatorial speeches, but any senators who think it contains a provision for a vote of no confidence might need to study it some more. Some senators seem to think it's their confidence in a Cabinet officer-or lack of it-that should determine whether he continues to serve. They are, to put it mildly, dead wrong.

No doubt about it, Alberto Gonzales wouldn't win any popularity contests in the U.S. Senate-or in the country. For that matter, neither would George W. Bush. But maybe that's one reason the founders settled on a fixed term for the president of the United States, so that the executive branch wouldn't come to resemble a revolving door, with its chief officials leaving office whenever their popularity waned. The founders took pains to separate the executive and legislative branches of government, rather than allow one to dismantle the other.

Here is what Trent Lott, the Mississippi senator, told his colleagues as they solemnly debated a parliamentary vote of no confidence: "This is a non-binding, irrelevant resolution proving what? Nothing." And then he added: "Maybe we should be considering a vote of no confidence on the Senate or in the Congress for malfunction and an inability to produce anything." A decent immigration bill, for example.

Expressions of no confidence, like resolutions of censure, can backfire. And at last report, Congress was doing even more poorly than the president in the polls. The Los Angeles Times/Bloomberg poll just found that Congress' approval rating had fallen "to its lowest level in more than a decade"-27 percent, which was down from 36 percent in January. Compare that showing with the president's 34 percent approval rating, which is no great shakes, either, but it's better than Congress'.

Yet the Senate is inviting a constitutional confrontation with the executive branch by issuing subpoenas for former White House officials like presidential counsel Harriet Miers and political director Sara Taylor-the kind of subpoenas a long list of presidents from Thomas Jefferson to Harry Truman have stoutly resisted. And for good reason. For the power to subpoena is the power to destroy, and once the executive branch submits to such inquisitions, its independence is compromised. It becomes answerable to the legislative branch, which is not how the American system is supposed to work-as opposed to a parliamentary system.

No wonder the American people are losing confidence in this Congress.