Be a great bullshitter. Really, that's what you need. Exploit logic, take things out of context, find loopholes, lie. People eat that shit up.
I thought a simple answer fitted a simple question, but almost everything a mind can excel at can be valuable. Good memory, verbally strong, logically strong, confidence, knowing how to read people, etc.
Being able to make the other guy look like a complete idiot even though you ae the one who is full of shit.
Which will stop working for you when someone sees through your BS, confronts you with it and lays it all out to see for everybody.
Being loud and not afraid to talk over the debated and the moderator. At least that seemed to be the pattern for the presidential debates and who was declared the winner of each.
Depends on what your goal is. If its to persuade college professor types, then you need logic and such. If its to persuade normal people, then you need to be able to appeal to their emotions.