Less likely, he could simply run out of new things to say. “You have to presume he can’t dominate the media for five more months this way,” Weber said. “What happens to him when the attention starts to dry up?”

Trump will face a tough early test in Iowa, where the Republican caucuses have been dominated by Christian social conservatives —not his natural constituency.

“If he comes in third or fourth in Iowa, he could lose his cool,” one strategist said. “If he looks like a sore loser and says he was robbed, that could cause the floor to fall out.”

On the other hand, another strategist told me, “The Southern primaries [in February and March] are a huge opportunity for him. If he wins enough of those, the rest of the field will collapse because their money will dry up. At that point, it becomes Trump versus someone else, an anti-Trump — probably Rubio, Walker, Kasich or Bush. And then it’s a real race.