WASHINGTON - President Bush appointed a conservative former judge and a moderate former Democratic senator Friday to head a special commission to "figure out why" inspectors haven't found the weapons that intelligence experts said Saddam Hussein was hiding in Iraq.

Bush told the panel to report back to him by the end of March 2005, well after the November elections and two years after U.S. troops invaded Iraq.

"Some prewar intelligence assessments by America and other nations about Iraq's weapon stockpiles have not been confirmed," Bush said in the White House briefing room. "We are determined to figure out why."

Democrats reacted to the new commission with skepticism. They wondered whether any panel picked by the president could be impartial, and they said its findings should be reported before, not after, the presidential election.

"To have a commission appointed exclusively by President Bush investigate his administration's intelligence failures in Iraq does not inspire confidence in its independence," said House Democratic Leader Nancy Pelosi of California.

Carl Levin of Michigan, senior Democrat on the Armed Services Committee, said the commission's assignment was diluted with less-than-urgent intelligence matters at the expense of examining "exaggerations of that intelligence by the Bush administration."

Bush said the panel would be bipartisan - co-chaired by Chuck Robb, the former governor and senator from Virginia, and retired judge Laurence Silberman.

Robb, son-in-law of the late President Johnson, has been practicing law since leaving the Senate. Silberman, who served as deputy attorney general in the Nixon and Ford administrations, was named to the appeals court by President Reagan in 1985.

Current Sen. John McCain, R-Ariz., was among the five other members named by Bush.

The commission is charged with examining intelligence on weapons of mass destruction and related 21st century threats, Bush said. The panel will compare what has been found by the Iraq Survey Group, which is still scouring Iraq for information about Saddam's arms, with information the administration had in hand before U.S.-led forces invaded Iraq in March 2003.

It also will review U.S. intelligence on weapons programs in countries such as North Korea and Iran, Bush said. In addition, the panel is charged with reviewing spy work on Libya before leader Moammar Gadhafi committed that nation to rid itself of nuclear, chemical and biological weapons, and on Afghanistan before the Taliban rulers were ousted.

Bush also named to the panel: Lloyd Cutler, former White House counsel to Presidents Carter and Clinton; former federal judge Patricia M. Wald; Yale University president Richard C. Levin, and Adm. William O. Studeman, former deputy director of the CIA. Wald, a former chief judge for the U.S. Circuit Court of Appeals for the District of Columbia, served as a judge on the International Criminal Tribunal for the former Yugoslavia.

Bush said two other members could be named later.

McCain said forming the commission was a wise decision. "In our war against terrorism, it is imperative that we guarantee the credibility and effectiveness of our intelligence capabilities," he said.

Wesley Clark, a Democratic candidate for president, said Bush was using the panel to affix blame to the intelligence community instead of to policy-makers, including himself, who used the information to make decisions.

"Waiting until 2005 for the commission's report simply is not acceptable," Clark added. "If there is a major threat posed by these weapons, we should have that information in 90 days, not a year from now."

Loch Johnson, a University of Georgia professor and former congressional and White House intelligence staffer, said he thought it was a mistake for the commission to broaden its inquiry beyond the focus of Iraq.

"They're going to broaden it so much that they're going to dilute the main focus and the reason we need this commission in the first place," he said.

He said the commission should focus on such questions as: "How good was the intelligence and to what degree was it bent, if at all, to suit the needs of the administration?"