At the unofficial start of the 2016 GOP presidential campaign here in Iowa, the race is already too sprawling ... Here are a dozen keys to understand what is happening now: 1. The candidates who have run before — Mitt Romney, Mike Huckabee, Rick Santorum — all think they can get their teams back together for another race. They can't. 2. Chris Christie is in better shape than you think. 3. Foreign policy has become as important as social issues, and that means people will listen to John Bolton. 4. Romney loyalists are deeply ambivalent about another run. 5. The...