Lindsey Graham might be the next sitting Republican U.S. senator headed to a runoff courtesy of a tea party challenge from his right.

Last week we saw Mississippi U.S. Sen. Thad Cochran forced into a runoff with challenger Chris McDaniel. The smart money, such as it is, says Cochran’s in trouble in the June 24 runoff. McDaniel is well-positioned to knock off the six-term Republican incumbent, who the tea party says isn’t conservative enough for Mississippians.

Instead, the Mississippi Republicans may nominate someone backed by fanatics who broke into a nursing home where Cochran’s wife has lived for more than a decade and who sought to produce an anti-Cochran campaign video that included images of his bed-ridden wife. Disgusting.

And what about Graham, another conservative who’s been deemed too squishy because he has the audacity to work across the aisle at times? Why, that turncoat even has supported some of President Obama’s judicial nominees, which angers the tea party faction in South Carolina to no end.

He’s got a boatload of challengers. The South Carolina GOP primary is Tuesday. The question there is whether Graham can be re-nominated without having to go to a runoff. If he doesn’t get the requisite 50-percent majority, can he prevail in a runoff in which the turnout usually is a whole lot lower than it is in the primary?

This is big news just about everywhere, it seems, but Texas. The tea party wing of the GOP is running strong here, so it’s no big deal to see “establishment” incumbents getting thumped.

Elsewhere? That’s another matter.

Stay tuned for the latest drama to play out Tuesday in South Carolina.