More thoughts on the outcome of a contested convention, from a friend with deep knowledge of past Republican campaigns:
Surely the success or failure of a brokered convention depends on one person, and one person only: Romney.
If Romney realizes that he cannot win easily on the first ballot, he has essentially three choices: cut a deal with Santorum, give up gracefully and let the convention choose a nominee, or try to fight. If the former, there's probably peace in Tampa, though I imagine many Romney supporters would not be happy. If he bows out gracefully, the positive possibilities are endless—and your nightmare scenario is most unlikely for the simple reason that there would be a larger number of former Romney delegates there who would not be susceptible to Bryan or Palin or anything along that line. But if Romney tries to fight in a grab for power despite months of mounting evidence that he is unpopular among Republicans and probably weakening in the country as a whole, then yes, this could get unpleasant. But if he would take the party down with him, why should anyone support him?
I welcome a brokered convention. It would almost certainly not pick one of the current candidates but instead ask someone to come in to serve the country. Given the nature of the delegates, we'd be back to the old, winning formula: pick the most moderate pro-life candidate. Jeb Bush, Mike Huckabee, or Mitch Daniels seem the likeliest choices. If there's a surprise, I assume it would be Chris Christie.
If the last month has taught us anything, it is how weak Romney is a candidate, both among Republicans and the electorate as a whole. Last month it was "electability" as the Romney theme; now it's "let's just settle on Mitt, otherwise it hurts electability." Surely both cannot be correct. Why do Romney supporters seem to be always finding these diversions to take attention away from Romney himself?