"His campaign ought to be reimbursing the Treasury for the cost of this trip," Boehner said.
White House press secretary Jay Carney countered that Obama's trip was focused on an important policy issue and said the president goes strictly "by the book" in drawing the line between campaign travel and official travel.
FEC rules specify that when there is any political activity at a particular stop, all travel to that destination must be reimbursed.
When a presidential trip includes multiple stops, some of them for political events and some for official purposes, then travel costs get divided up between the campaign and the government. But following a decades-old White House tradition, Obama aides declined to share details on how that's done.
Asked about Obama's reimbursements, White House spokesman Eric Schultz said the administration follows all federal rules governing reimbursements.
Meredith McGehee, policy director of the nonpartisan Campaign Legal Center, said the lack of transparency about how costs are divided up is troubling.
"It's a pretty murky business," she said. "Is the campaign paying its fair share? The answer is, we don't know."
Ari Fleischer, who was Bush's White House press secretary, said presidents of both parties need leeway "to do normal things," and that includes campaigning. They don't have the option of traveling commercial or charter airlines, or losing the security and support entourage that always travels with a president.
But Fleischer said Obama seems to cross a line by striking an overtly political tone at non-campaign events, such as a recent speech in Florida on tax fairness and the so-called Buffett Rule, in which the president criticized the economic policies of some "members of Congress and some people who are running for a certain office right now, who shall not be named."
Political rhetoric is in the ear of the beholder, however.
"I don't think the president is doing anything that is out of the norm," says Michael Feldman, who worked in the Clinton White House. "When he's talking about the Buffett Rule, he is campaigning for a piece of legislation and an administration priority in his capacity as president."
The Republican National Committee on Thursday requested a Government Accountability Office investigation into what it said were campaign stops being passed off as "official events."
Every recent president has faced finger-pointing over taxpayer-subsidized travel.
While the president's ability to swoop in to political events on Air Force One is a huge advantage — and a bargain — for his campaign in many respects, it does come with a downside: It's far easier for a challenger to hopscotch the country on a smaller plane and to quickly change plans as political dynamics shift. The high per-hour cost of Air Force One, for example, includes charges for fuel, supplies and short- and long-term maintenance for a plane unlike any other.
The cost breakdown for trips that involve a mix of political and official stops is particularly complex. And both Obama and his predecessor tended to mingle their fundraising with official travel, according to information compiled by CBS News' Mark Knoller, who tracks presidential travel.
From the day he filed for re-election through April 9, Obama had taken 58 domestic trips, including 23 that involved political fundraising. Seventeen of those fundraising trips also included official events.
Whether a presidential event should be considered official or political is an unending source of controversy.
Kathryn Dunn Tenpas, who studied presidential travel for the Brookings Institution, said it's difficult to draw a clear division.
"The office is inherently political," she said. "I'm not sure how you would ever separate the political from the presidential."
Associated Press writer Jack Gillum contributed to this report.
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