In an interview, Graham said the answer is simple: He was mad because the whole thing felt like a sham to him; because the process made the Senate look bad and a “good man” look worse; and because when Democrats nominated Sonia Sotomayor and Elena Kagan, Graham had voted to confirm them.

He knocked down the theories floated by armchair shrinks on cable news panels and professional rabble-rousers such as Bill Maher who have wondered aloud whether the recent death of John McCain, Graham’s close friend and mentor, has left the South Carolinian rudderless and without his moral compass.

It’s a compelling hypothesis: Graham calls McCain a giant of the Senate; McCain used to lovingly call Graham “Little Jerk.” They walked to voting sessions together and often cast their ballots the same way, even when it bothered others in their party.

“I said my goodbyes,” Graham said. “It was just me and John and Cindy and he said ‘Keep it going, boy,’ and I said, ‘I will.’ ”

Still, he said, “I’m not living my life going forward around John McCain.”