If they brokered both the POTUS and VPOTUS nominations it would likely be Rubio - Kasich.
Rubio has the name recognition for establishment Republicans and Kasich is in there because he's sane and has political experience. Kasich has too little name recognition to be the nominee but he's perfect for a VPOTUS nomination. Sane, a team player and not likely to screw things up for the POTUS nominee.
A brokered solution won't bring in Fiorina because they are going to naturally prefer people with political experience over those without any. The base might like outsiders and it sounds good for a while but when you get into the general election you want someone with some sort of experience or Hilary will pound them on that.
I also doubt they would select Bush because of his name. Nothing personal against Jeb but convincing people to create a situation where one half the last 6 presidents is a Bush AND not getting too tied up with his brother's administration is a hard sell.
So of all those ideas you suggested for a brokered nomination, I think Rubio - Kasich is only realistic choice.
However I agree I don't think they would go for a brokered solution. It would be political suicide on a number of levels. First it would send a lot of Republicans out of the fold because they would feel their vote didn't count in the primaries and that the insiders basically took over. They would likely form a 3rd party or join one of the other small conservative parties and nominate the guy who won the vote. (Likely Trump)
Secondly even if that didn't happen it would be too easy to attack them and their nominee on. A nominee chosen by the elites within the Republican party over the wishes of their voters. You couldn't set that up more perfectly for Hilary to knock out of the park. And of course the selection say it's Rubio would have to spend the entire time defending the very process by which he was nominated by and not being able to tell the American people why he would be a good president or at the very least better then Hilary.
Good analysis. I agree on most points but come to a different conclusion about the most likely ticket.
Bush-Kasich
Sure, both of them have proved to be crappy in the debates. I'm not sure they would be equally crappy one-on-one but even if they are, they could just minimize the number of debates and hold them early, so they have a smaller lasting effect.
Rubio is by far a better debater than Bush. But he's being criticized for his (lack of) campaigning chops everywhere other than the debate stage.
Rubio also faces the complaint that Rs have been throwing at Obama for 8 years: inadequate experience.
Plus, he's Hispanic. Which might be a good thing with the increasing H demographic. But he's Cuban, which is a very different Hispanic sub-demo. And, unlike most other Cuban-Americans, his family didn't flee Castro's Cuba but, rather, Batista's Cuba. Batista being the US-backed dictator that Castro overthrew.
Moreover, Rubio has noticeably backed off his earlier support for bipartisan immigration reform. And the GOP, in general, hasn't been making many inroads among H voters.
And finally, Rubio is sort of an anchor baby. He's a natural born citizen only if you agree that being born here despite being born to non-citizen parents makes you a natural born citizen. Rubio's parents became citizens after he was born.
Personally, I don't care about any of those objections. Because I'm a liberal. And maybe they won't matter to that many Rs. But you know they will be used against him. And since the Rs have been pushing those memes for a long time, that could put off some R voters.
And then there's the mistress thing. Another issue that liberals don't care much about, but conservatives might.
