President Obama’s endorsement of same-sex marriage is resonating on multiple local levels. In states where same-sex marriage has been at the forefront of public debate, the president’s position may have caused some black voters to reconsider their stance on gay marriage, recent polls indicate. And it’s making a difference in Minnesota, too, where voters in November will go to the polls to decide on a constitutional amendment that would define marriage as a relationship between a man and a woman.

After Obama’s endorsement of gay marriage in May, the phones at Minnesota United for All Families’ campaign headquarters were ringing off the hook.

“The next day, we didn’t have enough chairs for everybody wanting to work with the campaign,” the anti-amendment group’s press secretary Kate Brickman told TPM. Volunteer interest “definitely swelled,” she added.

A survey to be released Tuesday from Public Policy Polling (D) indicates a “big shift” against the amendment over the past four months. A January PPP poll of Minnesota showed that 48 percent of voters support the amendment, while 44 percent are opposed. The results fell along generational lines: voters under the age of 64 oppose the amendment. Seniors support the amendment 58/32.

Brickman said she wasn’t surprised to see PPP announce that Minnesota is seeing a shift against the amendment. “The momentum has been accelerating more and more,” she said. “Following North Carolina and Obama’s statement, people really started talking about it.”