Rick Santorum and Newt Gingrich campaign events have seen protests in recent days over the candidates' opposition to gay rights.

Santorum gave a 39-minute speech Sunday in the ballroom at the Sanford Center in Bemidji, Minnesota. Roughly 560 people showed up to hear what the GOP presidential candidate had to say.

According to the Bemidji Pioneer, protesters opposed to Santorum's record on gay rights lined up outside the building. Protesters held up signs saying, “Gay rights are human rights” and “I love my family – why doesn't Rick?”

Republican voters caucus in Minnesota and Colorado and cast ballots in a statewide primary in Missouri on Tuesday.

Gingrich on Monday faced hecklers during a campaign stop in Minnesota, CBS News reported.

“Hey Newt, why do you support discrimination against gays and lesbians all the time? Serial hypocrisy!” Gabe Aderhold of the Minnesota-based Gliterrati shouted.

Aderhold is the high school teen who heckled Michele Bachmann and Tim Pawlenty at the Iowa State Fair last summer. The teen asked both former candidates if they thought he was “a second-class citizen.”

“No hate in our state, why do you discriminate?” a second Gliterrati member shouted at Gingrich after Aderhold was pushed out of the room by the crowd. (The video is embedded in the right panel of this page. Visit our video library for more videos.)

Gingrich, who is looking to Minnesota to gain on rival Mitt Romney, appeared unruffled by the interruptions.

(Related: Newt Gingrich showered with “gay” glitter.)