“I wouldn’t be doing this if I wasn’t strong in South Carolina,” he tells NRO.

In a 2016 field crowded with at least half a dozen credible candidates, South Carolina operatives say, Graham’s worst-case scenario could be getting to play kingmaker for the eventual Republican nominee. “If we have three candidates, hell no; if we have seven, absolutely,” says one in-state consultant. A stronger showing could put him in line to replace John Kerry at the State Department if Republicans retake the White House. And maybe, just maybe, he could walk Arizona senator John McCain’s 2008 path through New Hampshire and South Carolina all the way to the nomination.

The biggest problem with that dream scenario: Graham is a man without a ready-made national base. He doesn’t command the allegiance of the establishment donor class, and he doesn’t have credibility with the Republican grassroots. Several county GOP groups in South Carolina voted to censure him last year after he helped to write an immigration bill that conservative activists hated. And to win reelection in 2014, he had to “wipe out the Tea Party,” as longtime friend Katon Dawson, the former South Carolina Republican Party Chairman, puts it. Grassroots conservatives won’t give Graham the kind of small-dollar donations that long-shot candidates need to win.