Santorum spent the day in Western Washington, splitting time between Olympia and Tacoma.
As he spoke at the Washington Historical Museum in front of an estimated 500 people, police escorted rowdy protesters out of the building.
Many remained and chanted against the former Pennsylvania senator.
Santorum arrived in Olympia Monday just as Governor Chris Gregoire signed the state's gay marriage bill into law.
Santorum, a socially conservative Republican, is against same-sex marriage.
Santorum is targeting voters who already support him and his ideals.
At noon, he met with so called "value voters" in a closed door meeting in Olympia.
A 3:00 p.m. meeting with Republican House and Senate leaders was also closed to the public.
Santorum has been riding a wave of popularity the past few weeks, stunning front runner Mitt Romney with key wins in the midwest.
Washington state's caucus is in about three weeks.
Notorious for never meaning much, Washington is now attracting a lot of attention from candidates because the state's March 3 caucus comes right before Super Tuesday.