Obama in support of gay marriages

President Barack Obama's support for gay marriage has not boosted his popularity among voters.

United States President Barack Obama. Picture: AFP.

WASHINGTON - President Barack Obama's show of support for gay marriage has inflamed political passions but has not given him a bump in popularity, a Reuters/Ipsos poll showed on Tuesday.

Roughly a third of Americans view Obama more favourably and a third less favourably because of his announcement that he supports the right of gay and lesbian couples to wed.

Obama said his backing of gay marriage was a personal decision but he has set off fierce political debate along with speculation about whether it will help him in November's presidential election.

Thirty-one percent of Americans have a higher opinion of Obama because of his gay marriage decision and 30 percent see him less favourably. Forty percent say the announcement had no impact on their view of the president.

Independent voters in the political middle who normally hold the key to victory in presidential elections were also split, with 19 percent viewing him more favourably and 26 percent less favourably. Fifty-four percent of independents said it had no impact on their opinion.

Mitt Romney, the presumed Republican presidential nominee, opposes gay marriage, although the issue has detracted from his efforts to focus the campaign on Obama's economic record.

Republicans and Democrats held sharply divergent views. Fifty-three percent of Democrats in the poll said they saw Obama more favourably after his shift, while 56 percent of Republicans regarded him less favourably.

Ipsos pollster Julia Clark said the split in support over gay marriage could be helpful to Republicans, who she said were historically more successful at mobilizing their supporters over hot social issues.

"The extreme polarization that we see in that breakdown between Democrats and Republicans is ... pretty substantial," said Ipsos pollster Julia Clark.

"When we look at the two groups separately, I think it could definitely move things around and impact on the race in the coming months, depending on who's able to mobilize more effectively," she said.