The Republican candidates for president have scheduled stops all across Wisconsin as part of a final push to win the state's April 3 primary.

The uptick in campaigning comes as a poll released Tuesday shows Mitt Romney, the front runner and former governor of Massachusetts, with a slight lead over Rick Santorum, the former U.S. Senator from Pennsylvania.

Romney has yet to campaign in the state, while Santorum spent all weekend in Wisconsin and was back on Tuesday. Along with former House Speaker Newt Gingrich, both planned to speak Saturday at an event organized by the Wisconsin Faith and Freedom Coalition in Waukesha.

The fourth candidate, U.S. Rep. Ron Paul of Texas, was to make his first appearance in the state at a town hall meeting Thursday on the University of Wisconsin-Madison campus. Gingrich was slated to hit the state Thursday with a rally at Marquette University in Milwaukee. His wife Callista, a Wisconsin native, has been campaigning in the state since Monday.

There are 42 delegates at stake in Wisconsin's April 3 primary.

The poll released Tuesday by the Marquette Law School showed Romney with 39 percent support of likely voters, with 31 percent for Santorum. Paul had 11 percent while Gingrich lagged at just 5 percent. A full 12 percent were undecided.

The poll reverses findings from February, when Santorum led Romney 34 percent to 18 percent. That survey was conducted when the Santorum campaign was at its high following wins in Minnesota, Missouri and Colorado. Since then, Romney has won in the Midwest states of Ohio and Michigan.

The telephone poll of 349 likely voters in the Republican primary was conducted Thursday through Sunday. The margin of error was 5.4 percent.