Both sides of the gay marriage debate agree on this much: The issue defines what sort of nation America will be.
Half a dozen states and the District of Columbia have made history by legalizing it, but it's prohibited elsewhere and 30 states have placed bans in their constitutions.
Obama supports legal recognition of same-sex marriage, as a matter decided by states. Romney says same-sex marriage should be banned with a constitutional amendment.
The debate divides the public down the middle, according to recent polls, and stirs up passion on both sides.
In November, four states have gay-marriage measures on their ballots. In Minnesota, the vote is whether to ban gay marriage in the state constitution. Voters in Maine, Maryland and Washington state are voting on whether to legalize gay marriage.
Thus far, foes of gay marriage have prevailed in all 32 states where the issue reached the ballot.
Petitions for Referendum 74 , which would provide a public vote on gay marriage, wait to be counted Wednesday, June 6, 2012, in Olympia, Wash. Washington's gay marriage law was blocked from taking effect as opponents filed more than 200,000 signatures for the referendum, which would put it to a public vote in November. Preserve Marriage Washington submitted the signatures just a day before the state was to begin allowing same-sex marriages. State officials will review the filings over the next week to determine whether the proposed referendum will qualify for a public vote, though the numbers suggest the measure will make the ballot easily. (AP Photo/Elaine Thompson)