Support for Minnesota's proposed gay marriage ban has dropped 5 percent in the last 4 months.

Voters in November will decide on the amendment which would define marriage as a heterosexual union in the Minnesota Constitution.

According to a Public Policy Polling survey of 973 Minnesotans released on Tuesday, more voters now oppose passage of the amendment than support it.

Voters who said they support the ban decreased from 48 percent four months ago to 43 percent today, a 5 percentage point drop, while opposition increased from 44 to 49 percent.

Sixty percent of younger voters, those under 45, oppose the amendment, while 50 percent of voters over 45 support it. A large majority (75%) of voters believe the relationships of gay couples should be legally recognized with either marriage (43%) or civil unions (32%).

Pollsters gave President Barack Obama credit for increasing opposition to such bans.

“The pro-equality side is now winning on gay marriage ballot initiatives in Maryland, Maine, Minnesota and Washington,” said Dean Debnam, president of Public Policy Polling. “The landscape has changed significantly since Barack Obama announced his support for gay marriage.”