BEAVER DAM, WI (WTAQ) - There are no presidential primaries on this Tuesday – and that means Wisconsin is the candidates’ next target, along with Maryland and Washington D.C.

All three have primaries a week from Tuesday. But Wisconsin is considered to have the closest race among the four Republicans who are still in it.

Rick Santorum was leading in several polls until a Rasmussen survey last week had Mitt Romney pulling ahead.

Santorum is due back in Wisconsin Tuesday night in Beaver Dam and Janesville, after he made five appearances last weekend.

Romney, Newt Gingrich, and Ron Paul are due in later this week. And in the meantime, Gingrich is sending his wife Callista on a swing of at least 9 Wisconsin cities Tuesday through Thursday. She was born in Whitehall in western Wisconsin.

Romney, meanwhile, is campaigning in California – and he’ll be on NBC’s “Tonight Show” with Jay Leno this evening.

The AP says Romney has just under half the delegates he needs to win the Republican nomination – 568 to 273 for Santorum, 135 for Gingrich, and 50 for Paul.