What most haven't spelled out: how they would address the latest international crisis if they were in the White House.
"You have a spectator in chief, not a commander in chief," former House Speaker Newt Gingrich groused Thursday in Greenville, S.C., trying to make clear his position on the subject after a series of conflicting statements.
Gov. Haley Barbour of Mississippi called Obama's response to the situation "dithering." Ex-Gov. Mitt Romney of Massachusetts said Obama has been "tentative, indecisive, timid and nuanced." Former Gov. Tim Pawlenty of Minnesota said Obama erred by not forcing a no-fly zone more quickly.
Since the Middle East uprisings began and spread across North Africa to Libya, the crop of presidential hopefuls have been quick to cast Obama as unfit to lead a foreign crisis and themselves as logical alternatives — but have been light on details of how they would govern.
Their latest round of attacks came as U.S. forces have enforced no-fly zone over the North African nation to protect rebels trying to oust Libyan leader Muammar al-Qaddafi — just as the Republicans demanded.
The candidates' hesitancy to weigh in with alternative solutions is somewhat understandable. They aren't receiving the same national security briefings as Obama on which to base decisions, and the crisis is still unfolding. It's also still early; the slow-to-form Republican field will have the better part of the next year to detail foreign policy visions and display international affairs credentials.
But as they embark on what's effectively a national job interview in which they're introducing themselves to GOP primary voters and the nation, the candidates must convince the public that they are ready to lead a nation juggling a host of international conflicts. Failing to provide details on how they would govern could undercut their efforts to cast themselves as credible challengers to an incumbent wartime president.
"What the Republicans should not do is flip-flop on whether the purpose of the action was just," said Michael Rubin, a scholar at the American Enterprise Institute, a conservative think tank in Washington. "If they called for a no-fly zone before President Obama imposed it, they will look ridiculous to oppose it a week later. Leadership is a fair campaign issue; cynically using the military as a political football when Americans remain in harm's way should be beneath any serious Republican or Democratic candidate."
He added: "I don't think any Republican candidate is going to step up to the plate and give precise military advice, but you might have them make arguments for better enunciated war aims."
Republicans traditionally enjoy an advantage on national security issues; a January AP-GfK poll found 48 percent of adults trusted Republicans as a better protector for the country to the 39 percent who favored Democrats.
The lack of specifics on foreign matters has dogged other first-time presidential candidates.
During the 2008 presidential primary, Democratic opponents hammered Obama for being inexperienced on international issues. The fresh-faced freshman senator from Illinois eventually developed binders of comprehensive policy and doled them out in speeches in the early nominating states to prove he had a foreign policy agenda.
So far, the GOP candidates have largely all followed the lead of House Speaker John Boehner, R-Ohio, who has criticized the president as authorizing the military actions without a clear goal and without enough consultation with Congress. The candidates also say Obama is too slow and too reliant on international approval from the Arab League, the United Nations and NATO.
Gingrich, the former House Speaker from Georgia, has faced criticism for his comments on the crisis. He demanded a no-fly zone after Obama said Qaddafi needed to be ousted. Then, Gingrich viewed the focus shifting to a humanitarian mission; Gingrich said he didn't support U.S. involvement for that objective. He also said in one interview that air strikes would oust Qaddafi and then said jets would not be able to end his rule now that fighting had gone into the cities.
Romney, who came up short in his 2008 White House bid and is to enter the 2012 race next month, has said he supports the mission in Libya. He's just not a fan of the president who started it or his approach to international affairs.
"Thus far, the president has been unable to construct a foreign policy, any foreign policy," Romney told Hugh Hewitt's radio show. "I think it's fair to ask, you know, what is it that explains the absence of any discernible foreign policy from the president of the United States?" He didn't detail what the Libya policy would be under a Romney administration.