Republican presidential hopeful Rick Santorum engaged in a heated exchange with a few students on gay marriage when he spoke to the 2012 College Convention on Thursday in Concord.

Santorum, trying to build upon his second-place finish in Iowa, spoke of the need to protect life and liberty, including opposing abortion rights.

Two of the first three questions were about his opposition to gay marriage. The second question on the issue came from College Convention participant Rhiannon Pyle, of Newburyport High School in Massachusetts, which led to a handful of testy exchanges with the student audience at the Grappone Conference Center.

Santorum received a mixed reaction; some audience members cheered him while others, particularly students, jeered him.