Updated

More Americans are embracing gay marriage, adding to calls from Democrats for President Barack Obama -- who has said he is not sure where he stands -- to publicly express his support before the November elections.

Obama opposes gay marriage, but for nearly the last 18 months has said his views are "evolving." Now he is under pressure to make support for gay marriage part of his party's election platform when he formally accepts the Democratic nomination in September.

Los Angeles Mayor Antonio Villaraigosa, chairman of the Democratic National Convention, said last week that a gay-marriage plank should be part of the platform, echoing recent comments from House Minority Leader Nancy Pelosi (D-Calif.). Gay-rights activists say they have been making the case to the White House that polls show Obama has little to lose politically if he endorses gay marriage.

Forty-nine percent of Americans now say they approve of gay marriage, up from 40 percent shortly after Obama took office in 2009.

Click here for more on this story from The Wall Street Journal.