WASHINGTON — Mitt Romney is Deb Bartholoma's man — for now.

"It varies from day to day," says the 53-year-old Republican from Timmonsville, S.C., where she is a county government official. "I'm listening to everybody."

That's typical of the uncertainty rampant in the three important early voting states in the struggle for the GOP presidential nomination. In-depth polling by The Associated Press and the nonpartisan Pew Research Center shows that in Iowa, New Hampshire and South Carolina, no one is a shoo-in.

Across the three states, tight battles are being waged for voters' trust on Iraq, immigration and other key Republican issues and for control of pivotal groups, including conservatives, white evangelicals and men. And it is Romney, not national front-runner Rudy Giuliani, who is ahead in New Hampshire and fighting for the lead in Iowa and South Carolina — three very different races. Former Arkansas Gov. Mike Huckabee has been surging lately in Iowa but is having trouble expanding his appeal beyond white evangelical Protestants.

Underscoring the tumult so far, only in Iowa do more than half of Republicans — 57 percent — say they strongly support their favorite candidate. That figure is lower in New Hampshire, 49 percent, and South Carolina, 44 percent, in an indication that many have yet to make up their minds.

As for Giuliani, the former New York mayor is seen as the most electable candidate by Iowa and South Carolina Republicans and is tied with Romney in that category in New Hampshire. However, solid majorities in each state say that is less important than finding a candidate they agree with on the issues.

Further complicating Giuliani's chances, one-fifth of Iowa Republicans and more than one-tenth in New Hampshire and South Carolina say they cannot support him — a distaste only Arizona Sen. John McCain and Rep. Ron Paul of Texas approach. Giuliani is on his third marriage and has more moderate views than many Republicans on gays, guns and abortion.

"A guy you can't trust in his home and family, how can he be trusted to run a nation," Jesse Hill, 26, a pastor in Unionville, Iowa, said of Giuliani. Hill supports Huckabee.

Giuliani campaign officials have said that even without momentum-building victories in the earliest states, he can win the nomination by doing well later in Florida, New York, California and other big states.

According to the AP-Pew poll:

• In Iowa, where the Jan. 3 caucuses will provide the nation's first votes, Romney has 25 percent support among Republicans, Huckabee 24 percent, Giuliani 14 percent and former Tennessee Sen. Fred Thompson 12 percent.