Sen. Bernie Sanders's (I., Vt.) support for extending voting rights to violent felons such as Dylann Roof, the racist gunman who murdered nine people at a black church in South Carolina, could prove problematic as the Democratic presidential candidates set their sights on the Palmetto State primary on February 29.

Roof, who recently filed an appeal challenging his conviction and death sentence, is a widely despised individual.

So is Dzhokhar Tsarnaev, the Boston Marathon bomber who killed 3 and injured nearly 300 others in 2013. Like Roof, he is on death row. Sanders would not only spare their lives by abolishing the death penalty but would also grant them voting rights in prison.

The subject of felon voting came up during a CNN town hall in April 2019. A member of the audience asked Sanders if he supported "enfranchising people like the Boston Marathon bomber, a convicted terrorist and murderer," as well as individuals convicted of sexual assault.

Sanders confirmed that he would extend voting rights to "terrible people," including those convicted of violent crimes, as part of his mission to create a "vibrant democracy" in America.

"If somebody commits a serious crime, sexual assault, murder, they're going to be punished," said Sanders. "They may be in jail for 10 years, 20 years, 50 years, their whole lives. That's what happens when you commit a serious crime, but I think the right to vote is inherent to our democracy. Yes, even for terrible people."

Days later, Sanders doubled down on his support for giving murderers the right to vote in a USA Today op-ed, offering "no apologies" for his position. "The right to vote is an inalienable and universal principle that applies to all American citizens 18 years and older. Period," he wrote.

Sanders is the only candidate in the Democratic field who supports granting voting rights to all incarcerated individuals. Entrepreneur Andrew Yang supports allowing some inmates to vote, so long as they "haven't prevented someone else from losing their ability to vote," a Yang spokesman told the Washington Post. Sen. Elizabeth Warren (D., Mass.) said she'd be willing to have a "conversation" about giving current inmates the right to vote, while the remaining candidates support restoring voting rights for former inmates.

The issue of voting rights for incarcerated individuals has gone largely unmentioned since the April town hall, but it could potentially resurface as the Democratic candidates head to South Carolina, the site of Roof's horrific shooting rampage. If Sanders performs well in Iowa and New Hampshire, his opponents might be compelled to mention his support for letting one of the state's most high-profile murderers vote in our elections.

The Sanders campaign did not return a request for comment.