“A lot of folks were scratching their heads over his decision, particularly because on a range of political issues, Rand had shown himself to be more strategic and pragmatic in his long-term political thinking than say Ted Cruz and Mike Lee,” said one Republican operative, who requested anonymity to speak candidly. “Fortunately, there was ultimately no harm but for anyone courting the Republican big donor community you can’t have too many missteps like that.”

What puzzled many in North Carolina Republican circles wasn’t the endorsement itself, which Paul made very early in the campaign in October, but the one-day appearance on his behalf earlier this week. In their view, Paul was wasting his time to help a candidate who had failed to catch on and stood nearly no chance of making even a primary run-off.

If anything, however, Paul was lucky he didn’t muster much support for Brannon. If he had won, Republicans nationwide would have blamed Paul for boosting an unelectable candidate. After successive Senate cycles of blowing winnable races by tapping people who could not win, Republicans – and especially Republican donors – are still sensitive about picking disastrous nominees.

Asked why he was campaigning with a candidate who had been found to mislead investors, sources close to Paul noted that Brannon had appealed the ruling and believed he was innocent.