(CNN) - Sen. Cory Booker on Monday called out Sen. Bernie Sanders over his support for restoring voting rights to convicted felons still serving prison time, drawing a rare explicit contrast with one of his 2020 rivals.
In an interview with PBS Newshour, Booker called the debate over voting rights for incarcerated felons "frustrating" and suggested it distracts from the larger, more urgent question of mass incarceration, which has been a policy focus of Booker's campaign.
"So, if Bernie Sanders wants to get involved in a conversation about whether Dylann Roof and the (Boston) Marathon bomber should have the right to vote, my focus is liberating black and brown people and low-income people from prison," Booker said, recalling mass attacks in recent years. Roof killed nine black churchgoers in South Carolina in 2015; the Boston Marathon bombing killed three people and injured hundreds others in 2013.
The New Jersey Democrat added: "My focus is tearing down the system of mass incarceration, so that we don't even have to have the debate about people's voting rights, because they're not going to prison in the first place. People that don't belong there are there, and I'm going to stop that as president."
A Sanders campaign aide told CNN later Tuesday: "We're proud to stand in solidarity with major civil rights groups in unequivocally declaring that the right to vote is inalienable." The comment was in reference to a joint letter from civil rights groups encouraging candidates to support extending voting rights to people in prison.
Booker has previously vouched his support for allowing felons to vote once they leave prison, as have other Democratic presidential hopefuls. But Sanders went one step further during a CNN town hall in New Hampshire earlier this month, during which he was asked whether he would advocate even for the Boston Marathon bomber, terrorists and others to vote — and he said he would.
"My own view is that the right to vote is inalienable if you are an American citizen," Sanders told CNN in a separate interview last week. "Not whether you're rich or you're poor, you're white or you're black, not whether you're a good person or a not good person. It is inalienable."
In a CNN poll released Tuesday, 28% of Democratic voters said it is "very important" that the nominee supports restoring felon voting rights, regardless of whether they have finished their sentence. Among non-white Democrats, 35% said it is "very important."
Sanders continued to promote his position in a Tuesday op-ed for USA Today, suggesting he remains comfortable on this political turf and hopes to keep this issue at the forefront. The Vermont senator has been trying to improve his standing among non-white voters, particularly African Americans, who will be a key Democratic constituency in the primary.
Booker, for his part, has struggled to break through among the crowded field of Democratic candidates. In the latest CNN national poll, in which Sanders polled at 15% behind former Vice President Joe Biden, Booker's support registered in the low single digits.
CNN's Gregory Krieg and Eli Watkins contributed to this report.
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