WASHINGTON (AP) -- President Barack Obama is facing mounting pressure to express support for same-sex marriage after a setback for gay-rights advocates in North Carolina.

Republicans there turned out in force Tuesday night to vote to strengthen the state's gay marriage ban. The passage of the state constitutional amendment proves that the topic remains a powerful election-year wedge issue despite tough economic times. It also illustrates the risks for the president as Democrats press him to do what no other has before - back gay marriage.

Obama appears ready to add his voice to this week's debate in a Wednesday afternoon interview with ABC News that the White House hastily arranged.