Off his list of places he can win, that is. Whether Newt Gingrich knows it or not — and I suspect he finally does — it is over for his presidential campaign. He was counting on an upset victory in Delaware. Instead he has lost by nearly 30 points. At the moment, that is the only state where Gingrich is even running second.

With Rick Santorum out of the race, Gingrich was supposed to be able to harness the remaining anti-Romney vote. He could press the idea of a conservative alternative all the way to the convention in Tampa, keeping Mitt Romney honest by reminding him that he still had fences to mend with the Republican base. He could have ended his campaign respectably, perhaps even with a Southern primary win or two.

Tonight shows that is unlikely to happen. Romney has won Delaware, Connecticut, Rhode Island, and Pennsylvania without any resistance from Gingrich. As I write this, the former House speaker is in fourth place in the Keystone State. Gingrich was already trailing in Texas and who knows what polls will show in North Carolina, the two best opportunities for keeping Romney from running the table in the remaining primaries.

Santorum was at least waving the anti-Romney banner and Ron Paul is building a movement for his supporters within the GOP. Newt is doing neither. There is no meaningful reason for Gingrich to carry on.