All of this being said, Christie would be wise to stay in the race. Bush has taken away Christie’s status as the safe establishment choice. Walker has taken away the top issue Christie has used to appeal to conservatives — toughness with public sector unions.

But who’s to say that either of them can keep their current momentum going? I’ve already outlined Bush’s weaknesses. Walker is only just now getting the kind of scrutiny a top-tier Republican presidential candidate can expect to receive. It can be even worse than what the unions threw at him in Wisconsin.

There are those who argue that Christie’s money problems are overblown. He doesn’t have a super PAC yet, while Bush already does. The Daily Mail’s Francesca Chambers quoted a Republican strategist as saying, “There’s not a finite amount of money or people in this business.”

There’s also not a lot of loyalty, especially among establishment Republicans.