I don’t believe Al Greene was impersonating Al Green. It’s just that that South Carolina has ignorant democrat voters who voted on name recognition, nothing else
I'd find the name quasi-recognition more feasible if Al Green had had a gold record or a Top 20 hit in the past 36 years.
But he hasn't.
I'm going to stick with my theory: that if there are two candidates whom you know nothing about and one of them robocalls you during dinner, you vote for the one who didn't robocall you.
According to Rawl's campaign manager, Rawl robocalled almost every registered Democrat in the state the night before the election. In his view, that made Rawl's loss unthinkable. In my opinion, it would have made Rawl's loss likely.