This excludes Alaska, Hawaii, and the individual electors representing Maine and Nebraska's congressional districts.
Market will close on election day, and I will try to resolve within a week of the election, ideally when all states have been called by multiple different news outlets.
Some additional clarifications that will probably not be relevant:
Corner adjacency doesn't count; UT does not border NM and AZ does not border CO
If Republicans win zero states in the contiguous 48 states, then this question resolves as YES
Michigan can serve as a bridge, e.g. if Republicans win MI+WI but Democrats win MN/IL/IA, then WI can still connect to e.g. IN or OH.
Arbitrage with https://manifold.markets/ManifoldPolitics/which-party-will-win-the-us-preside-c2b132de8821?r=U2VudGllbnRUcmVl.
Resolves NO if Dems win NC & GA, Reps win NH, or Reps win ME