Since only millionaires and morons vote for Republicans, and the majority are not millionaires, what does that make the majority, if not all, of the Republicans?

Well, let’s look at the syllogism and see:

If not A, then B

Premise A = majority of Republicans are millionaires
Premise B = majority of Republicans, if not all, are morons
Conclusion = Since a majority of Republicans are not millionaires, then the majority, if not all, of Republicans are morons.
QED [MSH] M-O-U-S-E