The country's leading gay rights group is donating $1 million to campaigns in four states where gay marriage is on the ballot this fall.

The Washington, D.C.-based Human Rights Campaign is donating $250,000 apiece to allies in Maine, Maryland, Minnesota and Washington. It brings the group's total spending on the issue this year to nearly $5 million.

Voters in Maine are voting on whether to legalize gay marriage. In Minnesota, the vote is whether to ban gay marriage in the state constitution. In Maryland and Washington, voters will decide whether to uphold laws authorizing gay marriage passed earlier this year.

Polls have shown increasing support for gay marriage around the country, but so far backers have not been able to translate that into a ballot box win.