Well the simplest game theory is (100% chance to be nominated now but near 0% chance to be confirmed) vs (??% chance to be nominated later but 90%+ chance to be confirmed) which seems fairly straightforward. Given current outlook for POTUS election I would decline in their shoes. An older nominee or one that expected 8+ years of GOP presidents might reasonably say this is their only chance and take it though.
I guess an interesting question is whether being nominated now and not approved or stonewalled until withdrawn disqualifies you from being nominated again. I think the default answer is 'yes' (disqualified) although various circumstances could allow it to happen.
This seems like very unreasonable estimate. Being election season, the Republicans will be sensitive to public opinion and stalling for 9+ months could cement the perception of being obstructionists. If Obama nominates a somewhat moderate candidate, they may decide to live with it.
