Washington ? White House political mastermind Karl Rove surrendered a key policy role Wednesday and press secretary Scott McClellan resigned in an escalation of a Bush administration shake-up driven by Republican anxieties.

Rove gave up his responsibilities as chief policy coordinator, a position he assumed just over a year ago that strengthened his influence over matters ranging from homeland security and domestic policy to the economy and national security. The promotion had left him stretched too thin in the eyes of some officials, as the White House grappled with mounting problems.

With Wednesday’s change, Rove will be able to focus more on politics, fundraising and big-picture thinking with the approach of the November congressional elections, officials said.

A major force in the administration from the start, Rove still is expected to have a significant voice in policy but not the day-to-day oversight. Those responsibilities will shift to Joel Kaplan, who was promoted to deputy chief of staff from the No. 2 job in the White House budget office where he had served as Joshua Bolten’s lieutenant.

Bolten took over Friday as chief of staff with authority to do whatever he deemed necessary to stabilize Bush’s presidency, and he has moved quickly with changes.

With the Iraq war hanging over President Bush, the White House has been rocked by mistakes and missteps – from an ill-fated Supreme Court nomination to a bungled response to Hurricane Katrina – that have resulted in the president’s plunge in polls to the lowest point since he took office. Nervous Republicans told Bush he needed fresh people with new ideas.

McClellan out

McClellan, the press secretary for nearly three years, was the public face of the White House and a vulnerable target in an administration trying to show off new people. He had been bloodied by contentious press briefings and media criticism about an administration loath to release information.

President Bush, from left, Deputy Chief of Staff Karl Rove and White House Press Secretary Scott McClellan walk back into the White House on Wednesday, after a problem developed with Bush's helicopter. Rove is giving up his policy management duties and McClellan is resigning, in a continuing shake-up in Bush's administration.

“The White House is going through a period of transition. Change can be helpful, and this is a good time and good position to help bring about change,” McClellan said, his voice choked with emotion as he stood alongside Bush outside the White House. “I am ready to move on.”

In recent months, McClellan had told people he enjoyed his job and wanted to stay for the long term. He said Wednesday he started to think about leaving in the past few weeks and concluded, with a new chief of staff, that it was a good time to go. He and Bush came to a decision in a meeting Monday in the Oval Office.

“I have given it my all, sir, and I have given you my all, sir, and I will continue to do so as we transition to a new press secretary,” McClellan said.

“It’s going to be hard to replace Scott,” Bush said. “But, nevertheless, he’s made the decision and I accept it. … Job well done.”

Bush patted McClellan on the back and they walked together across the South Lawn to the president’s helicopter to begin a trip to Alabama. But the aircraft couldn’t get off the ground because its radio failed, and they had to take a motorcade to the airport.

McClellan will remain until a successor is named. Possibilities mentioned include Tony Snow, host of a program on Fox News Radio; Dan Senor, former coalition spokesman in Iraq; Trent Duffy, former White House deputy press secretary, and former Treasury spokesman Rob Nichols.

More to come

More changes are expected but not before next week. White House officials have done nothing to discourage speculation that Treasury Secretary John Snow is leaving. Bush’s communications chief, Nicolle Wallace, also is expected to depart because her husband has taken a new job in New York. Changes also are expected in the White House lobbying shop run by Candida Wolff.

The shake-up began with the March 28 resignation of Andy Card, Bush’s longtime chief of staff, and his replacement by Bolten. Just this week, Bush has named a new budget chief and a new trade representative and is moving toward choosing a new domestic policy adviser

Kaplan, the new deputy chief of staff, will take over from Rove as coordinator of policy developed within the Domestic Policy Council, the National Economic Council, the National Security Council and the Homeland Security Council. A trusted aide to Bolten, he will be the new chief’s right-hand man.

“Joel Kaplan is a man of great talent, intellect and experience who possesses a deep knowledge of policy and budget processes,” Bush said in a written statement.

Rove and Joe Hagin, who oversees White House administration, intelligence and national security, will remain as deputy chiefs of staff.

Rove still is under investigation by Special Counsel Patrick Fitzgerald for his role in the leak of Valerie Plame’s CIA identity. Democratic National Committee Chairman Howard Dean said the change in Rove’s role was mere “window dressing.”

“From the collapse of the president’s scheme to privatize Social Security to Rove’s involvement in the outing of a covert CIA agent’s identity while he still holds a security clearance, the president has abundant reason to fire Karl Rove,” Dean said in a statement.

The CIA leak episode also brought problems for McClellan. He at first denied Rove had played any part in the leak, saying he based his account on Rove himself. But later it was revealed that Rove had been a source for at least two reporters.

McClellan said Kaplan would focus on the day-to-day management of the policy process. “And so this really frees Karl up to focus on bigger strategic issues,” the spokesman said. “He will continue to be a crucial voice and trusted adviser on policy … as he has since the beginning of this administration.”