With a flurry of coast-to-coast developments this week, same-sex marriage is back in the political spotlight and likely to remain there through Election Day as a half-dozen states face potentially wrenching votes on the issue.

In Maryland, New Jersey and Washington, bills to legalize same-sex marriage have high-powered support and good chances of passage in the legislature.

Gay-marriage opponents in Maryland and Washington would likely react by seeking referendums in November to overturn those laws, while New Jersey’s Republican governor, Chris Christie, says he’ll veto the bill if it reaches him and prefers that lawmakers OK a referendum so voters can decide.

In all three states, polls suggest voters are closely divided on whether gays should have the right to marry, so there’s a chance one could emerge as the first state to support same-sex marriage in a statewide vote.

Maine voters also may have an opportunity to vote for same-sex marriage in November; an announcement by gay-rights activists about a ballot-measure campaign is set for today. Proposed amendments for constitutional bans on gay marriage will be on the ballots in North Carolina on May 8 and in Minnesota on Nov. 6.

In New Hampshire, Republicans who now control the legislature are mulling whether to repeal the 2009 law legalizing same-sex marriage. Their state is one of six with such laws, along with Connecticut, Iowa, Massachusetts, New York and Vermont, as well as the District of Columbia.

Added together, the state-level showdowns will likely raise the prominence of the marriage issue in the presidential campaign, even though it’s not a topic that the leading candidates tend to broach proactively.

“There’s a lot going on,” said gay-marriage advocate Evan Wolfson, president of Freedom to Marry. “It means that candidates — whether Romney or Obama — who hope to avoid the discussion will not be able to.”