Republican presidential candidate Rick Santorum is headed to Washington state Monday, planning campaign stops in Olympia and Tacoma, as he fires up his campaign for the March 3 GOP caucuses.

Santorum plans to meet with foes of gay marriage in Olympia in the afternoon, and then will hold a campaign rally at 7 p.m. at the Washington Historical Museum in Tacoma, according to a copy of the plans distributed to state GOP officials.

His visit comes on the same day that Gov. Chris Gregoire is expected to sign into law a bill that legalizes gay marriage in Washington state. The former Pennsylvania senator touts his conservative stance on social issues, including opposition to gay marriage.

It is the first scheduled visit from one of the Republican presidential contenders ahead of the state caucuses, which will be a prize this year with the party's nomination battle nowhere near settled.

Santorum has been riding a recent tide of popularity among Republican voters looking for an alternative to former Massachusetts Gov. Mitt Romney.

Romney also is planning a trip to Washington on March 1.

Meanwhile, President Obama is scheduled to attend a couple of fundraisers and an official event in Seattle on Feb. 17.