Here is true wild card possibilty
Lets say that Romney loses Virginia (a flip from my prediction), Nevada BUT wins Colorado, North Carolina, Iowa (a flip from my prediction), Florida (looking worse than I thought), and Ohio (chaos due to 200,000 provisional ballots)
This leaves him at 268 to Obama’s 270, BUT Romney is barely ahead in the 2nd congressional district in Maine, which, if he wins, would give him ONE extra EV, thus 269-269 tie, with the House electing him POTUS, and the Senate voting Biden VP, split White House for the first time since 1804.
Super, super long shot, but that will tear the nation to shreds if this nightmare scenario does occur. Combine Ohio and Florida super close (and probably VA), plus the split EV in Maine, plus Obama winning the popular vote, plus the racial elements. Civil War II Lite.
A VP Biden with a President Romney would be a pain, but could do little of consequence if Romney did not permit it.