Doubts about Bush administration policy in Iraq (search) - past, present and future - take center stage at the Capitol with the start of hearings Tuesday.

With casualties mounting and increased fears the United States lacks an effective plan for success, lawmakers are debating how America got into the dangerous predicament and how it will get out.

"Time is rapidly running out on getting it right in Iraq," Sen. Joseph Biden of Delaware, top Democrat on the Senate Foreign Relations Committee (search), said recently.

Sen. John Warner, R-Va., chairman of the Senate Armed Services Committee, said he remains "steadfastly optimistic," adding, "We'll see our way through this."

But worry about events in Iraq crosses party lines. Iraq is the topic before three committees this week.

In three days of hearings beginning Tuesday, the Foreign Relations Committee looks at how U.S. occupation forces will transfer political power June 30 to an as-yet unnamed Iraqi government.

Also set to start Tuesday are two days of hearings on the military part of the effort. Top Pentagon (search) officials are testifying first before the Senate Armed Services Committee, then the House counterpart.

The hearings come during the deadliest month in Iraq for U.S. forces since the invasion began - 100 killed in the increasingly violent insurgency. Some estimate over 1,000 Iraqis have died, including civilians, insurgents and police.

Many lawmakers who were in their districts on the just-ended spring recess faced constituent questions about Iraq.

Because the violence and the stalling of some reconstruction efforts have come so recently, they are not reflected in polls already showing an increase in the number of Americans who think troops should come home and lower support for the president's handling of Iraq. Already, almost six in 10 of those surveyed say he does not have a clear plan for success in Iraq.

Republicans say Bush eased some American concerns with his news conference last week by pledging to stay the course in Iraq. Democrats say he did not because he was short on details.

Officials are likely to face questions at the hearings on what is being done to calm the violence, whether troop levels are high enough and exactly how the administration intends to work with the United Nations.

U.S. occupation authorities, who long shunned a substantive U.N. role in Iraq, are now counting on it to help devise a plan for forming a new Iraqi government to accept sovereignty on the turnover date.

Democrats probably will focus on mistakes they say got American forces to this point. Those include too few troops sent over in the first place, a lack of planning for postwar operations, unilateral action that has left the United States bearing the bulk of the financial and human toll, and overly optimistic predictions on what it would take to oust Saddam Hussein (search) and build a new democratic government in his place.

Those problems, Democrats say, were on top of the fact that the administration appears now to have used faulty intelligence to justify the war. Many officials now believe Iraq did not have weapons of mass destruction the administration sent American troops to find and destroy.

It also was during the congressional recess that the Pentagon went back on its promise to send troops for one-year deployments. The government has extended the tours of thousands of troops by three months, ordering them to remain there due to the increased violence.