According to the latest poll of Wall Street Journal / NBC News was conducted in the beginning of March, it's almost 60% of Americans who support equal marriage against 30% in 2004.
Fred Yang, the Democratic pollster who conducted the survey with Republican Bill McInturff said public opinion about gay marriage is changing at a much more rapid rate than did the nation’s attitudes toward interracial marriage, which now is supported by 87% of Americans.
The survey shows that the most important supporters are still among Democrats and those between 18 and 34 years. The survey also shows an increase in support in the Hispanic community and women.
It also shows that opposition among conservatives fell. In 2013, the Conservatives who supported same-sex marriage represented only 26%. Today, they account for 35%.
Is observed in particular a clear increase from 2013 to 2015 among Republicans. 27% of Republicans supported equal marriage in 2013 against 40% this year.