WASHINGTON - Facing growing dissatisfaction both inside and outside his presidential campaign, Sen. John McCain ordered a shake-up of his team Wednesday.

He reduced the role of campaign manager Rick Davis and vested political adviser Steve Schmidt with "full operational control" of his bid for the presidency.

Schmidt becomes the third political operative in the past year to take on the task of attempting to guide McCain to the White House. A veteran of President Bush's political operation, Schmidt will be in charge of finding a more effective message in his race against Democratic Sen. Barack Obama, who leads in most public polls.

In a telephone interview, Schmidt said McCain faces a difficult challenge, given the overall mood of the country, but said he is encouraged by the fact that Obama and McCain remain in a relatively tight race.

"There are 125 days left until the American people will decide the next president," he said. "Senator McCain is the underdog in the race. We suspect he is behind nationally 5 to 8 points but well within striking distance. I will help run an organization that exists for the purpose of delivering John McCain's message to the American people."

The abrupt shift in leadership, announced to McCain's staff Wednesday morning, came after weeks of complaints from Republicans outside the campaign and growing concerns within it about the lack of a clear message, the cumbersome decision-making process, the sloppy staging of events and a schedule driving largely by fundraising priorities rather than political necessity.

The problems crystallized this week, with McCain off on a three-day trip to Colombia and Mexico, where he is talking about trade and drug trafficking, an exercise even some insiders considered as a waste of the candidate's time.

Schmidt, who managed California Gov. Arnold Schwarzenegger's re-election and was a top aide to Vice President Dick Cheney, will have broad authority to revamp the campaign and its message in the coming weeks. He plans a renewed focus on the need to reform government, a theme that fits McCain's brand but has been largely lost in the daily discussions of the economy and national security.

Schmidt's goal is a less bureaucratic campaign structure that will allow for faster decision-making and more outreach to individuals and groups who can be helpful to McCain's cause. But his biggest challenge will be to help McCain deliver a clearer and more consistent message, and to do so in the right places.

"It addresses the need to put a professional in charge of message," said John Weaver, who was McCain's chief strategist but left in a July 2007 shake-up. "It is important that the campaign and the candidate respond to that in such a way so as to try to drive a message, which has been lacking."