The timing of the announcement was pretty surprising to me. I guess he thought he was going to lose in Pennsylvania.
Rick’s polling numbers in PA were falling. Can you imagine how bad it looks if he lost his own state? It simply means the people who know him best do not like him.
Newt won his state of Georgia, Mitt won MI & MA. If Rick lost PA, that wipes him out for good politically. So he was smart to quit before the final nails in the coffin were struck. He will now endorse the front runner in due time to secure a position in the admin.