Call it the perils of the late (albeit well-timed) surge.

Former Senator Rick Santorum told ABC News that although his campaign has raised more than $2 million since his strong showing in Iowa, the cash came too late to get any TV ads on in New Hampshire.

"We've raised a lot of money now but all the TV has been bought," Santorum said, "there's no place to get in. So you are sort of stuck having to run a grassroots campaign coming down the stretch. It's hard to make up 39 points in five days with a grassroots campaign."

Santorum made his remarks in a network exclusive interview in Dublin, N.H., which will air on World News with Diane Sawyer this evening.

"I have a pretty short window to sort of close the deal here," Santorum said, setting his bar at beating other more well-funded rivals in the second tier. "Hopefully we will eclipse some of the other folks that have been spending more time here, more money here than we have. We are not going to spend much money here."