President George W. Bush just lost the latest battle in his administration's long-running war with Congress. And, in this instance, the American people won.

For more than a year now, the House Judiciary Committee has been investigating the 2006 firings of nine U.S. attorneys for what appears to have been purely political reasons. Although U.S. attorneys are political appointees, and thus serve at the pleasure of the president, historically those positions, once filled, have been shielded from political influence, and properly so. Recent reports by the U.S. Justice Department's internal investigators have disclosed that some groups of potential civil service employees — honors program candidates and administrative law judges, for example — were subjected to an improper political litmus test. Another report expected soon will look at the U.S. attorney firings.

In its investigation of the firings, the Judiciary Committee had subpoenaed former White House Counsel Harriet Miers to testify and had sought documents from White House Chief of Staff Joshua Bolton in an attempt to determine if indeed there was improper White House influence into the U.S. attorney dismissals.

The White House asserted executive privilege, making the standard claim that the president needed to have unfettered communication with his aides, and rejected the congressional subpoenas. Congress rightly took the rejection to the U.S. District Court for the District of Columbia. There, Judge John D. Bates, a 2002 Bush appointee, strongly rejected the White House claims.

In his 93-page opinion, Judge Bates said, "The Executive cannot be the judge of its own privilege and hence Ms. Miers is not entitled to absolute immunity from compelled congressional process." He also appropriately urged a compromise between the two branches of government.

But this is why the American people won: As a separate branch of government, Congress has oversight responsibility over executive branch departments, including the Justice Department. Under the Constitution, Congress has the duty to make sure government works for the good of the nation, as it was doing here. To do so, its committees investigate wrongdoing, abuses of power and sometimes just plain ineptitude.

The White House, on the other hand, has a legitimate but highly limited tool in executive privilege. The problem is that since Watergate executive privilege has been more about hiding embarrassments or illegal actions than the constitutionally mandated separation of powers. In disputes, the third branch of government, the judiciary, determines what the law is, a principle first articulated in Marbury v. Madison in 1803.

President Ronald Reagan told his White House that executive privilege rarely was to be asserted. During the Monica Lewinsky investigation, President Bill Clinton tried and failed to use executive privilege to protect himself from embarrassment. On a number of issues and on an unprecedented level, President Bush has used executive privilege to strengthen the White House's hand against Congress and the courts. Judge Bates reasserted the Founder Fathers' constitutional principle of separation of powers with each branch of government serving as a check on the power of the other two.

REPRINTED FROM THE SAN DIEGO UNION-TRIBUNE.