ROCK HILL, South Carolina – Bernie Sanders made a pitch to black voters Friday at the First in the South Democratic Presidential forum here sponsored by MSNBC. But he also defended his record on guns and said the Democratic Party must do a better job of reaching out to white working class voters.

Close video Sanders: US has a voting rights crisis Democratic candidate Bernie Sanders explains how every American should have a right to vote, and calls Republican lawmakers that enforce any restrictive voting legislation “political cowards.” Democratic candidate Bernie Sanders explains how every American should have a right to vote, and calls Republican lawmakers that enforce any restrictive voting legislation “political cowards.” share tweet email Embed

The Vermont senator also showed off a lighter side, joking with moderator Rachel Maddow and declaring that his seven grandchildren “are the joy of my life. “

Black voters in the south, including this state, have been Sanders’ weakness in building durable campaign against frontrunner Hillary Clinton, but he made a direct ask for their votes. “I have the economic and social justice agenda that will resonate with African-American community,” he said. “I was there with Martin Luther King Jr. - Dr. King - in the March on Washington.”

Clinton has made Sanders’ record on gun control a key issue in the Democratic primary, but he said the challenger has “misstated” his views about the need to stop shouting on guns, which has become a flashpoint in the race and led to accusations of sexism.

RELATED: Clinton leans into criminal justice reform at MSNBC forum

It wasn’t the only shot he took at Clinton. Like former Maryland Gov. O’Malley, who spoke before him, Sanders chided Clinton for her late-arrival to opposition to the Keystone XL pipeline. “As opposed to some other unnamed candidates, the issue of Keystone was kind of a no brainer,” he said. “I said no the Keystone on day one.”

He said he doesn’t want to go negative on Clinton, saying he hates the pressure the media puts on him to attack the former secretary of state. “As well you know, Rachel, media drives me nuts,” he said.

Close video Sanders: We will end 'gun show loophole' Bernie Sanders discusses his views on gun control, saying he believes the “gun show loophole” should end, and that a “radical” change is needed to treat the mentally ill and prevent gun tragedies in the U.S. Bernie Sanders discusses his views on gun control, saying he believes the “gun show loophole” should end, and that a “radical” change is needed to treat the mentally ill and prevent gun tragedies in the U.S. share tweet email Embed

Sanders’ brightest moment Friday came when showed his sense of humor, which he rarely displays in public. He made a joke about his underwear – a reference to Larry David’s “Saturday Night Live” sendup of Sanders – and poking fun at himself.

The biggest misconception about him? “People think I am grumpy, people think I am too serious.”