Given the right circumstances, a skilled candidate can attack his way past one opponent. But Christie is stuck in a muddle with three other candidates—Rubio, Kasich, and Bush.

Or more accurately, Christie is stuck behind the muddle of Rubio, Kasich, and Bush—he’s been persistently at 5 percent in the New Hampshire polls. He went on a kamikaze strike against Rubio in the debate, and suddenly seems willing to denigrate Kasich and Bush, too. Heads-up with any one of them, you could see how Christie’s full-bore assault might work. But in order to move up enough to stay viable, Christie would have to leapfrog all three of them. And this seems highly unlikely.

It’s not true that there are no silver medals in politics—candidates can finish second (or third, sometimes) in primaries and still have paths forward. But with a 10th place finish and 2 percent of the vote in Iowa, and South Carolina looming next, a New Jersey Republican would have to do quite well in New Hampshire to have any productive reason for moving on. Christie might well have prevented Marco Rubio from having a good night tomorrow. But it’s unclear how he helped himself.