Photo Gallery: Photos of Obama’s Hawaii vacation

As Republicans who want to be president slog through chilly Iowa in the run-up to next week’s caucuses, the man who is president moves from one enviable sun-splashed outing to the next.

The contrast between President Barack Obama’s week in Hawaii and that of the Republican candidates couldn’t be more vivid, as the first family celebrates the holidays in a multimillion-dollar rental house near the turquoise waters of Kailua Beach.

Today, the president and his family went to Pyramid Rock Beach at the Marine Corps Base Hawaii for some private time at a beach known for its bodysurfing waves.

On Wednesday, Obama golfed at a course carved out of a forest in Kaneohe while, in Muscatine, Iowa, Mitt Romney took a swipe at rival Ron Paul over his stance on Iranian nuclear weapons.

The day before, Newt Gingrich accused Paul of avoiding “reality,” while Obama and his daughters released four green sea turtles into Hanauma Bay, a snorkeling paradise.

Incumbency has its advantages. Obama can afford the vacation, having no serious opposition for the 2012 Democratic nomination. He paid his dues in Iowa four years ago, when he staked his long-shot campaign against Hillary Rodham Clinton on a victory in the caucuses.

Splendid a time as he’s having after a tough year in Washington, Obama is taking pains not to rub it in. With Americans suffering through tough economic times, the White House has been careful to avoid photos of the president having too much fun.

He has been photographed greeting troops at a nearby Marine base, but not hitting a putt on a manicured green. Journalists were permitted to see him holding his daughters’ hands in a visit to a sea park, but not driving a golf cart.

Obama has been content to stay out of a news cycle dominated by the Republican race. White House press aides are on the trip, but are not giving the traveling press corps daily briefings. Reporters shouted a question to Obama on Tuesday about the Yemeni president’s request for a visa so he could travel to the U.S. to seek medical treatment.

“OK, guys,” Obama said, “good to see you. Hope you’re having fun.”

The politics of presidential vacations are tricky. Even Franklin D. Roosevelt, who pulled the country out of the Depression, faced public criticism for fishing off Navy cruisers, said Ross Baker, a political science professor at Rutgers University.

Obama, by greeting troops on Christmas Day, helped “inoculate” himself against “the charge that he’s basically off in lotus land while everybody else is suffering through the winter,” Baker said.

It all ends Monday. That’s when Obama returns to the White House, where plenty of real-world pressures await. He’ll need to jump back into negotiations to extend the payroll tax cut through the end of 2012. And his re-election campaign will begin in earnest.