President Obama's endorsement of gay marriage has not changed the minds of Americans on the issue.

But a new Associated Press-GfK poll shows that the move did fire up the president's liberal supporters and his conservative opponents.

The survey showed that 53 percent of Republicans strongly disapproved of his handling of the issue, compared with 45 percent in August. And 52 percent of conservatives say the same, up from 43 percent back then.

The issue could spur major turnout against Obama among those groups in November.

Meanwhile, a sizable portion of the public still opposes gay marriage. The poll shows 42 percent of Americans are against it, 40 percent support it, and 15 percent are neutral.

In every state where voters have been allowed to weigh in on gay marriage, they have rejected it.