I would say that before this year it would have been investment bankers. But from now on it would police officers. Investment bankers have too much to lose.
Did you sleep through the Democratic primaries this year, or do you just want the GOP to be a party comprised solely of poor, uneducated White racists THAT badly?
Even if Trumpism gains some momentum, you are ignoring the fact that the Democrats' base - whom they are ABSOLUTELY beholden to, as well (see Hillary becoming an ardent protectionist or Bernie pandering to BLM - literally HATES investment bankers. They talk about them like they are literally evil people for doing what they do. That's not changing anytime soon.
Dem base might hate whomever they like (though, it is by no means homogeneous), but the real threat to the US financial industry is Donald Trump. They would not like Bernie Sanders, but nobody is offering them Bernie Sanders. Hillary Clinton is perfectly acceptable to them. And, in any case, even Bernie would have been a lot less dangerous for their interests: at least, he is not openly calling for destruction of US credit.