Mitt Romney has an 8 percent lead over President Obama in the critical battleground state of North Carolina, according to a survey released Wednesday from conservative polling outlet Rasmussen.

Romney leads 51 percent to 43. The two were tied in the same poll taken one month ago.

While the poll could be an outlier — Obama leads in North Carolina by 2 percent, according to the Real Clear Politics average of polls — it could also mark a shift in support following Obama’s endorsement of gay marriage last week.

The day before Obama became the first sitting president to announce his support for same-sex marriage, voters in North Carolina overwhelmingly approved an amendment banning gay marriage.

That’s a headache for Democrats, who will hold their national convention there in September.

Obama defeated Sen. John McCainJohn McCainOvernight Defense: Senate panel passes defense policy bill | House panel presses on with markup | Trump officials say WH statement prevented Syria chemical attack | NATO pledges to raise spending Senate panel passes 0B defense policy bill GOP infighting erupts over healthcare bill MORE (R-Ariz.) in the Tar Heel State by less than 1 percent in 2008, which was the first time North Carolina had voted for the Democratic presidential candidate since 1976.

The survey of 500 likely voters was conducted on May 14 and has a 4 percent margin of error.