The NAACP of Maryland is launching a radio ad on Tuesday urging support of the same-sex marriage referendum on next month’s ballot, the group said.

Julian Bond, chairman emeritus of the NAACP. (Photo by Nikki Kahn/The Washington Post)

“I know a little something about fighting for what’s right and just,” Bond says in the ad, which the NAACP said will air in both the Washington and Baltimore markets. “Maryland’s gay and lesbian families share the same values, and they should share in the right to marry.”

The ad comes at an important time in the campaign on Question 6 and targets a key audience.

On Monday, television ads from opponents of the same-sex measure started airing, arguing that limiting marriage to a man and a woman has “served society well for thousands of years.”

Marylanders for Marriage Equality, the lead group supporting Question 6, plans to put up television ads starting on Wednesday.

African-American voters are seen by both sides as a key demographic. Opponents of same-sex marriage are working through black churches . Supporters were heartened this summer by endorsements of same-sex marriage by both President Obama and the NAACP.

In the new radio ad, Bond also argues that the issue is not primarily about religion. “I believe people of faith understand this isn’t about any one religious belief – it’s about protecting the civil right to make a lifelong commitment to the person you love,” he says.