Illinois: Has allowed civil unions since 2011. The state Senate passed legislation legalizing same-sex marriage, but the House adjourned without passing it. Advocates will press for a House vote by November because the bill is still viable; Gov. Pat Quinn (D) has vowed to sign it.
New Jersey: Has allowed civil unions since 2006. The legislature passed a bill legalizing same-sex marriage in 2012, which Gov. Chris Christie (R) vetoed. There is a push to override the veto by a January deadline and a push to overturn it in state court.
Hawaii: Allows civil unions and has a constitutional amendment saying marriage must be defined by the legislature. A group of legislators will push a bill to legalize same-sex marriage, a move Gov. Neil Abercrombie (D) supports.
Oregon: Has a constitutional same-sex marriage ban. Groups will begin circulating a petition July 20 to replace the ban with language guaranteeing same-sex marriage under a 2014 ballot initiative. They will need to gather 116,284 valid signatures by July 2014 to qualify the measure for the November general election.
Nevada: Has a constitutional same-sex marriage ban. Advocates are undertaking a legislative effort to put a measure on the ballot in 2016 to repeal the state's ban and replace it with a same-sex marriage amendment. The legislature passed a resolution in the 2013 session and will have to do so again in 2015 to refer the measure to voters in November 2016. The legislature is dominated by Democratic majorities, and the resolution does not require the signature of Gov. Brian Sandoval (R) to go on the ballot.
New Mexico: New Mexico's constitution does not specifically define marriage. The ACLU and the National Center for Lesbian Rights filed a marriage lawsuit in state court in March 2013 seeking legalization of same-sex marriage. Gov. Susana Martinez (R) opposes same-sex marriage, as do some Democrats and many Republicans in the legislature.
Indiana: Gay marriage foes aim to get an initiative on the ballot in 2014 defining marriage as between a man and a woman. Gov. Mike Pence (R) is in favor of this, as are many GOP legislative leaders.
Arizona: Same-sex marriage is banned, as are civil unions and domestic partnerships. Groups plan to gather signatures for an initiative to overturn the ban in 2014.
Colorado: Same-sex marriage is banned by the state constitution and by statute. The state allows civil unions and domestic partnerships, and proponents are looking at a ballot initiative.
Michigan: Same-sex marriage is banned, as are civil unions and domestic partnerships. A federal judge in Detroit is positioned to rule on a case challenging the ban, and bills have been introduced by state Democratic lawmakers to amend the constitution to allow same-sex marriage.
Montana: Same-sex marriage is banned, as are civil unions and domestic partnerships. Gay-marriage proponents are considering a push in the state because of its libertarian bent.
Ohio: Same-sex marriage is banned, as are civil unions and domestic partnerships. Groups are hoping to collect 386,000 signatures for a future ballot.
Pennsylvania: Marriage is defined in statute as between a man and a woman, prohibiting same-sex marriage, civil unions and domestic partnerships. House Democrats said they would introduce a bill to allow same-sex marriage, despite opposition from Republicans, most notably Gov. Tom Corbett.
Wisconsin: Same-sex marriage and civil unions are banned under a constitutional amendment, but there is a limited domestic partnership registry. A constitutional amendment would have to pass two consecutive legislative sessions and a statewide referendum. The domestic partnership registry has been challenged as violating the existing marriage amendment, and Lambda Legal is litigating the issue; groups are separately considering launching a legislative drive there.
Wyoming: A statutory ban on same-sex marriage allows recognition of gay couples married elsewhere. Civil unions were voted down this year. State representatives have described same-sex marriage as "four years out at best."
Virginia: Same-sex marriage is banned, as are civil unions and domestic partnerships. State representatives have said they will repeal the amendment ban, though the General Assembly must pass the initiative in two different years with an election for the House of Delegates in between before it can be voted on by the public in a referendum. The state Senate is split between Democrats and Republicans, and advocates say it will be a challenge to pass legislation given the current political climate.
Iowa: Gay-marriage opponents hope to pass legislation for two sessions in a row that would get an initiative on the ballot banning same-sex marriage once more, although it will be dependent on Republicans taking back the state Senate and keeping control of the House.