The Iowa Republican Caucuses may come down to a photo finish. Ted Cruz and Donald Trump are tied with 27% of the vote each. Apart from the 27 percenters, Marco Rubio takes 3rd place with 15%, with Ben Carson behind him at 9%. The rest of the field holds 18% of the support, with another 3% undecided. Unlike the Democratic Caucuses in Iowa, once you commit to a candidate, your vote is finalized. There is no support threshold, meaning the top candidates cannot benefit from lower tier candidates not getting enough traction. Slightly frustrating efforts to read into how this...