During a Republican presidential debate in South Carolina, former Pennsylvania Senator Rick Santorum slammed Mitt Romney over the issue of voting rights, calling the issue especially resonant on Martin Luther King Jr. Day.

From Think Progress comes this quote from Santorum, who was challenging an ad being run in South Carolina by a pro-Romney super-PAC, which accuses Santorum of supporting voting rights for felons. Said Santorum:

This is Martin Luther King day. This is a huge deal in the African American community because we have very high rates of incarceration, disproportionately higher rates particularly with drug crimes in the African American community. The bill I voted on is the Martin Luther King voting rights bill. And this was a provision that said — it particularly targeted African Americans. And I voted to allow them to have their voting rights back once they completed their sentence.

Read more at ThinkProgress.

Romney was the target of attacks during the Fox News debate, with the four remaining contenders for the GOP nomination hitting him for refusing to release his tax returns, and for his time as head of Bain Capital, which critics accuse of “vulture capitalism” for dismantling companies the firm acquired and laying off employees.

Romney is polling first or second in most polls from South Carolina. The primary will be held January 21st.

Related: Why Christian conservatives probably won’t stop Romney from winning nomination