President Obama's explanation of his own evolution on gay marriage is being used to swing voters in Maryland on a ballot measure legalizing same-sex unions. Maryland Politics reports:

One woman tells the other she made up her mind on same-sex marriage after hearing Obama talk about it. She tells her friend that she kept the clip of his endorsement on her mobile phone because “it’s that important.”

The ad, produced by Marylanders for Marriage Equality, highlights the emphasis both sides have put on wooing African American voters, who make up a larger share of the electorate in Maryland than in any state outside the Deep South.