Democrats presidential hopefuls criticized the Bush administration Wednesday for putting a political appointee in charge of the probe into the leak of a CIA employee's identity.

Attorney General John Ashcroft (search) recused himself from the investigation Tuesday after Justice Department personnel working on the case accumulated enough evidence to constitute a possible conflict of interest.

The investigation will be handed over to the U.S. attorney in Chicago, Patrick Fitzgerald (search), Deputy Attorney General James Comey announced in an afternoon news conference. Comey will be acting attorney general in the case, he said, and Fitzgerald will be the special prosecutor in charge of all decision-making related to the investigation.

"He has the power and authority to make whatever prosecutorial judgment he needs," Comey said.

Several Democrats complimented Ashcroft for his decision, but many of the party's presidential contenders said handing over the case to a special prosecutor was not good enough.

"The public will not likely trust the results of an investigation headed by a political appointee, especially when the special counsel is constrained by Department of Justice regulations that severely curtail the prosecutor's autonomy," said Sen. Joe Lieberman (search) of Connecticut.

"Whether it is a special counsel or the Justice Department inspector general, the American people deserve a person whose honesty, objectivity and fairness are guaranteed to investigate this serious matter," said former Vermont Gov. Howard Dean (search).

North Carolina Sen. John Edwards (search) did not criticize the appointment, but said Ashcroft's decision "comes far too late. President Bush knows how to get what he wants inside his White House, yet for months, his administration has somehow failed to find the person responsible for this dangerous and destructive leak."

Massachusetts Sen. John Kerry (search) called Fitzgerald's appointment "a half measure and nowhere good enough to restore public confidence in this tarnished agency."

He said Comey and Fitzgerald "are both Bush political appointees and carry the same baggage as John Ashcroft."

Despite the criticism, President Bush, vacationing at his ranch in Crawford, Texas, welcomed the news of a special prosecutor, said his spokesman Trent Duffy.

The president "wants to get to the bottom of this," Duffy said, adding that the White House was not consulted on the attorney general's decision to recuse himself from the investigation, and was only informed on Tuesday morning as a courtesy.

Other Democratic lawmakers also said they were pleased that Ashcroft was staying out of the case.

"For the sake of America's national security, I hope the administration will give the new counsel its full cooperation and the resources needed to quickly get to the bottom of this urgent matter and swiftly bring to justice the person or persons responsible," said Senate Democratic leader Tom Daschle of South Dakota.

"The attorney general has made the right decision. Our intelligence agents need to know that we understand the sacrifices they make and that we will come to their defense when someone puts them at risk. An independent investigation is the only way to restore their faith in the government they serve," Sen. Jay Rockefeller, D-W.Va., ranking member of the Senate Intelligence Committee, said in a statement.

But House Minority Leader Nancy Pelosi of California agreed with the presidential candidates that the Ashcroft recusal was too little, too late.

"The appointment of an exemplary U.S. attorney as a lead prosecutor does not obscure the fact that the CIA leak investigation remains accountable to, and ultimately under the control of, senior leadership at the Department of Justice," Pelosi said. "This national security breach must be investigated with the highest degree of independence — and the Bush administration investigating itself does not meet that test."

At the news conference announcing the change of leadership, Comey pre-empted criticism of the investigation, saying that Fitzgerald was the best person for the job because "he is [an] absolutely apolitical career prosecutor" who has a "sterling reputation for integrity and impartiality."

He added that recusals were a fairly common occurrence in the Justice Department.

"The issue surrounding the attorney general's recusal is not one of actual conflict of interest that arises normally when someone has a financial interest or something. The issue that he was concerned about was one of appearance. And I can't go beyond that," he said.

The flap originated with President Bush's State of the Union address last January, in which he claimed that British intelligence had found that Iraq tried to buy yellowcake uranium (search), needed for building nuclear weapons, from an African country.

Ambassador Joe C. Wilson (search) had been sent by the Bush administration to Niger, the African nation in question, in February 2002 to substantiate the claim but was unable to do so.

In July, Wilson, who has since endorsed Kerry for president, complained in a newspaper article that the Bush administration had exaggerated the yellowcake story as partial justification for toppling Saddam Hussein.

Administration officials later acknowledged they should not have included uranium allegation in the State of the Union address. But before that happened, the name of CIA employee Valerie Plame appeared in reporter Robert Novak's syndicated newspaper column.

Plame is the wife of Wilson, who claimed that her name was mentioned as retribution for his criticism. He also claimed, and then retracted, a suggestion that Bush senior political adviser Karl Rove (search) was the source of the alleged leak.

The leak of a covert operative's name is punishable by up to 10 years in prison and $50,000 in fines. Rove, a campaign consultant for Ashcroft when the latter was a senator from Missouri, has met with investigators, who also have interviewed more than three dozen other White House officials as well as Defense and State department and CIA personnel.

Novak refuses to name his source, but states that he or she is "no partisan gunslinger." He says the source accidentally mentioned Plame's name during a long conversation.

In September, CIA Director George Tenet officially asked the Justice Department to launch a probe into the leak of Plame's name.

Since then, Plame and Wilson have drawn a fair amount of publicity to themselves, including agreeing to pose for a photo spread in Vanity Fair magazine. Wilson also is releasing a book this spring detailing his life in the diplomatic corps and the leak case.

Fox News' James Rosen and Sharon Kehnemui and the Associated Press contributed to this report.