The only way either Hillary or Bernie Sanders can win is if Trump is the GOP candidate. He is the only one that will offend enough people to cause them to sit it out or vote for a Dem.
This election should be a cakewalk for the GOP. Except---Trump.
After this election BOTH parties are going to have to do some soul-searching about how they are going to change, and it won't be in the way anyone in the extremes of either party thinks. Both are going to have to turn to the middle. The GOP needs to figure out how they can attract a younger and more diverse electorate, and the Dems are going to have to disavow the socialism that has become part and parcel of their platform.
I am supporting Marco Rubio this election. I think he will send either Hillary or Bernie back to the old folks' home, whimpering in pain. I know a LOT of people are disgusted by his Gang of Eight sell-out, but let's get realistic: we have to do something about the millions of hard-working, otherwise law-abiding people who are here illegally. They are not going to be deported en masse, and people who are realistic know that.