As much as I love Bernie (and I do!) I honestly (and sadly) think that he is as unelectable as Trump. So H. Clinton might be a better nominee there.
GOP: As far as I can work out it’s almost a dead cert for a brokered convention, which is something I knew nothing about until I got obsessed with this crazy primary! However I now know this:
1) All delegate pledges are reset to zero- meaning that anyone is now able to stand for Republican nomination however:
2) As of 2012 only candidates who have acquired a majority in 8 states can put themselves forward (rule 40) but:
3) There is a meeting in July (before the convention) of the 112 member Republican rules committee that might change this so that people other than Trump/Cruz can stand.
Conclusion:
I think that the GOP mainstream are going to push for John Kasich or Paul Ryan to be their nominee for POTUS, and most likely get one of them just as long as they can agree who to push for! (Could also be Marco Rubio, Jeb Bush or in fact several others, even Mitt Romney. So many!!)
Sauce