Unless the bigger establishment names choose not to run (Bush, Christie), I just don't see Paul being the nominee. The media isn't focusing on his eccentricities right now and they certainly haven't attempted to tie him to any of his father's more "unique" views. And make no mistake, they will do that by late 2015 and early 2016.
I go back to a story recently written about the four factions of the Republican party. The author, Henry Olsen, suggests the four groups are moderates/liberals (25-30%), somewhat conservative, very conservative evangelicals (20%), and conservative secular voters (5-10%). The somewhat conservative group is the largest faction at 35-40% of the vote.
While Paul may start with the vast majority of the very conservative secular voters, that only gives him a base of 5-10% so he'll obviously have to branch out into other groups. He's making a serious play to do that now, but other candidates will likely fill those slots and make it difficult for him to piece together the 40% or so he'll need to win in a contested field. And the best evidence of that is the current RCP average. Paul sits at 13%, or just above the 10% threshold for very conservative secular voters.
These numbers also show why "establishment" choices have dominated since 1988. For instance, while Paul must significantly branch out, someone like Bush wouldn't need to do nearly as much. He'd likely occupy a major portion of the somewhat conservative faction and he'd almost certainly do well with the moderate/liberal portion. Just in raw numbers, that's as much as 70% of the primary vote. And even if Paul were to get every secular vote and evangelical vote, he'd still have to snag some from the two groups an "establishment" choice would dominate. And if Cruz is in the race, well he and Paul occupy the same sphere.
If Bush and Christie both decide to pass (that won't happen), then it's easier to see a path for Paul or Cruz, but the somewhat conservative and moderate/liberal factions dominate the primary. I'd put the number at 65%. It's why Romney survived and it's why neither Paul or Cruz is likely to win. And in my opinion, that especially true if Bush runs, because I think he'll clear a good part of the field that would've competed for the somewhat conservative and moderate/liberal votes.
I just don't see Paul or Cruz unless a whole bunch of people say no (Bush, Christie, Rubio, Walker, Kasich).
http://nationalinterest.org/article/the-four-faces-the-republican-party-9930
