With Capitol Hill consumed by the nation’s financial crisis, time is running out on the broader search to find out just what happened behind closed doors during the last eight years. As the Bush administration winds down, numerous congressional investigations on a range of issues from greenhouse gas emissions standards to the firings of federal prosecutors remain unresolved — blocked by the White House’s wide-ranging assertions of executive privilege.

Even before Wall Street’s woes put nearly every other agenda on the backburner in Washington, constitutional scholars were noting that Congress had been ineffective in responding to the executive branch’s sometimes unprecedented claims of a need for secrecy. Among the probes stuck in their tracks:

• The inquiry into Dick Cheney’s role in the administration’s leak of CIA operative Valerie Plame’s identity in 2003. House Government Oversight Chairman Henry Waxman subpoenaed the report of the FBI’s interview with Cheney after publication of former White House spokesman Scott McClellan’s book. McClellan claimed he had been misled on senior officials’ roles in the Plame affair. But the White House asserted executive privilege over the interview record in July.

• The investigation into whether the White House pressured the Environmental Protection Agency into blocking California’s efforts to enact stringent greenhouse gas emissions standards for cars and trucks. Waxman’s committee already has obtained documents showing that EPA scientific and legal staff were united in recommending the California program go forward, but the White House has concealed records of its dealings with the agency on the issue.

• The investigation into the EPA’s weakening of regulations on smog-forming ozone after an intervention by President Bush on the eve of the rules’ publication last March. The White House has claimed executive privilege over more than 1,000 records in this case. The EPA cases are unique, said Mitchel Sollenberger, constitutional law expert at the University of Michigan. “You have the president declaring executive privilege on a decision-making process that can be described as almost purely an EPA decision.”

• And overshadowing all of the other battles, the inquiry into the firings of nine U.S. attorneys in 2006. On Monday Attorney General Michael Mukasey agreed to appoint a special prosecutor to investigate whether laws were broken. But Congress’s investigation has been stymied, despite a federal judge’s ruling in July that the administration could not assert executive privilege to prevent testimony from former White House Counsel Harriet Miers or production of documents by White House Chief of Staff Joshua Bolten. The White House has appealed, a process that, at the very least, will run out the clock on the administration. It could also land the matter in the lap of a Supreme Court that scholars believe may prove deferential to the expansive Bush view of executive power.

The House Judiciary Committee’s decision to take the U.S. attorneys’ case to court was telling, said Sollenberger. “They are trying to vindicate their authority through another co-equal branch — which is really a sign of where the pendulum has swung in Washington.” In his view and that of other scholars, Congress shouldn’t be going to court, but using its own political tools in disputes with the executive branch — holding up appointments, or tying up the purse strings by refusing to grant the executive branch’s budget requests.

“Congress has ample powers to get the information it needs to protect its institutional interests,” said Louis Fisher, constitutional specialist with the Law Library of Congress. “But if Congress doesn't know its institutional interests, or is not willing to fight for them, the executive branch will prevail. Fundamentally, Congress is supposed to protect itself, not ask some other branch to do that.”

But for the most part, Congress has not escalated political battles with the administration over its executive privilege claims. In the case of the EPA decisions, Waxman wrote letters in August to the Justice Department, the EPA, and the White House Office of Management and Budget, asking them to describe the documents being withheld from his committee. But that was the last public step in the probe.

Waxman’s committee is now, of course, deeply involved in investigation of the financial crisis.