I really like Rand Paul, but engaging a debate of the cause or our involvement in WWII is TERRIBLE politics. Those were different times, and most people aren’t aware of all of the variables in play back then. There’s just simply nothing to be gained on his part by such a discussion or debate. In this political world comprised of 5 second sound bites and 30 second ads, you should ONLY say things that will HELP you.
You’re right about there being nothing to gain from discussing anything pre-historic (ie, anything before December 7th 1941). Everyone knows that nothing happened between the end of the the civil war and the first week in December of 1941. Cable teevee says so.