North Carolinians voted to change the state constitution Tuesday to say that the only valid "domestic legal partnership" in the state is marriage between a man and a woman. The amendment passed 61 to 39 percent, making North Carolina the 29th state with a gay marriage ban in its constitution.

The state already outlawed gay marriage, but the constitutional amendment makes it more difficult for politicians to ever change the law. The amendment also means that a handful of North Carolina municipalities that extended benefits to the domestic partners of their employees will no longer be able to do so, since marriage is now the only valid legal partnership in the state. Former President Bill Clinton urged the state's voters not to support the amendment in robocalls, while President Barack Obama's office said he was also against the change.

Supporters of gay marriage out-raised and out-advertised their opponents in the lead up to the vote, emphasizing in TV ads that the amendment could also have repercussions for unmarried straight couples because of its vague language. The anti-amendment coalition raised more than $2 million, according to campaign finance disclosures, most of which came from small and large individual donations. The pro-amendment crowd, called Vote for Marriage NC, raised a little more than $1 million, with most of the money being donated by nonprofit groups, not individuals.

Only 46 percent of voters realized that the amendment would ban civil unions for gay couples as well as marriage, according to a Public Policy Polling poll. A majority of North Carolina voters support civil unions.

Minnesota faces a ballot gay marriage ban in November, while Maine activists are hoping that residents have changed their minds and will vote to approve gay marriage this November after repealing its legalization in 2009. Lawmakers in Maryland, Washington and New Jersey passed laws legalizing same-sex marriage this year, though Gov. Chris Christie vetoed New Jersey's law.

Story continues

More popular Yahoo! News stories:

• Richard Mourdock defeats Sen. Dick Lugar in Indiana

• Obama using health care law to court Latinos

• RNC Hispanic outreach director: Romney 'still deciding what his position on immigration is'

Want more of our best political stories? Visit The Ticket or connect with us on Facebook, follow us on Twitter, or add us on Tumblr. Handy with a camera? Join our Election 2012 Flickr group to submit your photos of the campaign in action.