But with the campaign over and Obama in the White House, Graham's tune has changed. These days, he's the president's loyal opposition.
At the Newseum today, the South Carolina Republican encouraged Republicans to give Obama political cover to send more troops to Afghanistan--and to temper the more extreme anti-Obama voices on the right.
"There is a chance for the loyal opposition to become President Obama's biggest ally," Graham said, as the administration faces a difficult decision on whether to send as many as 40,000 troops to Afghanistan. "The Republican leadership must stand behind this president, and if he loses that...he's in a bad spot when it comes to Congress."
And Graham pledged his personal support: "I'm going to do everything I can to give him the political support he needs to win these two wars that we're in." With liberal opposition growing against sending more troops into war, it's cover the president could likely use.
As for the fringe elements of the right (the birthers, for example) Graham said Republicans have to call them out--have to police their own ranks.
"We have to say that's crazy," Graham said when The Atlantic's Jeffrey Goldberg asked him about the conspiracy theories that have sprung up on the right.
"So I'm here to tell you that those who think the president was born somewhere other than Hawaii are crazy. He's not a Muslim. He's a good man," Graham said. (A comment that prompted Goldberg to ask if the two are mutually exclusive. Some explaining ensued.)
When asked how he communicates that sentiment to the conspiracy theorists themselves, Graham was blunt: "When I go to town-hall meetings, say, 'You're crazy.' In a respectful way"--a comment the audience seemed to enjoy.
On the moral discrepancy between Republicans' conservative social values and repeated marital scandals, Graham said: "We're not gonna be impeded by sinners and nuts. That is not our problem."
Talk radio contributes to the right's less constructive tones, Graham suggested, drawing a parallel between the conservative airwaves and the left's MoveOn.org. When asked about Glenn Beck, the newest conservative-commentary phenom (though, as Graham noted, Beck isn't necessarily a voice of the conservative clique, but rather his own beast), Graham said:
"Only in America can you make that much money crying...I mean, you know, what [do] I think about Rush Limbaugh? Well, I think he makes hundreds of millions of dollars being able to talk on the radio."
But the real question, according to Graham, is: "how many people in my business are going to be controlled by what's said on the radio or in a TV commercial...Glenn Beck is not aligned with any party as far as I can tell. He's aligned with cynicism, and there's always been a market for cynicism."
There are just too many challenges facing the country to allow that cynicism to permeate, Graham implied.
Of all the scary situations facing America right now, Graham said Iran is one of the worst. A military attack is only a last resort if Iran's nuclear capabilities continue to progress, Graham said, but if that happens, he'd prefer to go all out.
"If the sanctions don't work...I think a military strike before they get a nuclear weapon would be in our best interest," Graham said. "I wouldn't just strike their nuclear targets, they would not have a conventional force left if I was president."
With the Republican Party at a critical moment--in a still-new minority, but with a wave of grassroots energy swelling up on the right--Graham's point was that the crazies can't be allowed to dominate the discussion, and that on critical elements of national security, Obama needs and deserves Republican backing.
"Do I want some of his policies to fail? You better believe it. Do I want him to fail? No, because he's my president," Graham said. "If he fails in Afghanistan, if he fails in Iran, my country fails."
Watch the full video of this session: