I have heard the theory and in addition to your comments that it is known he is pals with the Clintons.

Do I believe he is part of this election cycle to help the Clintons? Well, if he is, he is doing them a giant favor and I expect that Trump being Trump would only do that for a favor in return.

So, if following Hillary being elected president something falls in line in Trump's favor in a big way...well...I'm sure that theory looks a lot more solid. He certainly always has been liberal on social issues in the past and now is taking some stances that don't really fit with where he was before on these issues.

I think Trump only does what benefits Trump. So, how does he benefit from this presidential run and basically destroying the Republican party?

Yes, he probably gets some ego gratification out of it but it will be interesting to hear what he says when he loses. Also he has really made himself and by default his Trump brand look terrible doing this. Not sure if he is faking it for the Clintons but if he is he has put a lot on the line to do so for them.