While a lot can happen in the next six months I think Jeb has what it takes to win the presidency.
He's a fluent spanish speaker with a Latino wife who's pro immigration by republican standards. This means he'll get a higher percentage of the Latino vote, which is very key.
Jeb is backed by the Bush fund raising machine, which is 3-1 in presidential elections. He's also done fine work in Florida as governor, which is the key swing state in 2016.
While hard core conservatives might frown upon Jeb being too moderate on some issues, I think most of them who back Scott Walker would walk over broken glass to vote for Jeb over Hillary Clinton.
For what's it worth, I once briefly meet the man in a hotel in Orlando circa 2006. Jeb was there for some political event and waiting in the hotel lobby. I was 10 feet away from him waiting to check in. He saw me looking at him and said hello.
Jeb's a big man! He really stands out in a room. I'm 6'1" tall, and he had a least 2-3" on me. I thought Jeb had a regular guy vibe, and an easy smile about him. IMO, he can connect well with Joe average voter. If you didn't know who he was you'd think he was a friendly dad taking his kids to Disney world.