A supporter of same-sex marriage wears a rainbow flag in front of the U.S. Supreme Court. A supporter of same-sex marriage wears a rainbow flag in front of the U.S. Supreme Court last March. (Andrew Harrer / Bloomberg)

These are pins-and-needles days for lesbian, gay, bisexual and transgender Americans and all who hope the Supreme Court will restore meaning to the Constitution’s promise of equal protection under the law. Any day now (today, perhaps?) the highest court in the land will hand down its decisions in Hollingsworth v. Perry and United States v. Windsor.

Perry is known as the Prop 8 case because the suit seeks to invalidate California’s 2008 constitutional amendment banning same-sex marriage. Windsor is known as the DOMA case for its challenge to the so-called Defense of Marriage Act of 1996. The country has changed dramatically since either measure was put on the books. And if the high court tosses one or both anti-gay statutes, it will reflect where the nation is today rather than pushing it beyond where it’s ready to go.

A report due out Tuesday from the centrist think tank Third Way on the “State of Relationship Recognition in 2013” puts everything into perspective. “As of June 2013, 49.5 percent of the country—more than 150 million Americans—lived in a place with some sort of relationship recognition law for gay couples,” write the authors Sarah Trumble and Lanae Erickson Hatalsky. That’s half the country, folks. And support for marriage equality stands at 58 percent, according to the latest Post-ABC News poll.

They point out that marriage equality wasn’t legal anywhere in the country when DOMA became law 17 years ago. When Prop 8 cast a pall on Election Night in five years ago, same-sex marriage was legal in Massachusetts and Connecticut by court order. Today, there are 12 states, plus the District of Columbia, where same-sex marriage is legal. Half of those states adopted marriage equality in the last 12 months. And half of those — Delaware, Minnesota and Rhode Island — did so last month.

Last November, for the first time, voters approved marriage equality at the ballot box in Maine, Maryland and Washington state. Also for the first time, voters rejected a constitutional amendment banning same-sex marriage in Minnesota. That laid the groundwork for that state to fully adopt marriage equality last month. Many states already had domestic partnership or civil-union statutes on the books. But Trumble and Hatalsky argue that these laws are essential to, rather than a hindrance to, full marriage rights in states.

Of the 4 new marriage states [Delaware, Maine, Minnesota and Rhode Island], 3 [all but Minnesota] had already offered domestic partnerships or civil unions to gay couples in their jurisdiction. Colorado, the newest civil union state, had previously offered domestic partnerships. This indicates that the stepping stones of domestic partnership and civil union laws have been and continue to be crucial to our nation’s journey towards allowing all committed gay couples to marry. These interim laws provide legal protections in states where there otherwise would be none, and rather than thwarting progress towards marriage, they serve as an impetus to continue moving forward.

Depending on how the Supreme Court rules in the Prop 8 case, more states could join the gay wedding circle. The justices could hand down a narrow decision that finds Prop 8 unconstitutional but also rule that their decision only allows same-sex marriage in California. But Trumble and Hatalsky present another scenario that would be even more historic.

“[T]he Justices could hand down a ruling that says a state may not distinguish between relationships in name alone, and in doing so essentially legalize marriage in the seven states with civil union or domestic partnership laws that offer the same state protections as marriage,” the Third Way writers explain. Those states are Colorado, Hawaii, Illinois, New Jersey, California, Nevada and Oregon. “In that scenario, 41.5% of the country would live in states where gay couples could legally marry.”

If the court finds DOMA unconstitutional, then those legally married same-sex  couples would be viewed as such by the federal government. As Trumble and Hatalsky point out, it is highly unlikely that this Supreme Court will rule that there is a constitutional right to marry for same-sex couples. But what it might do short of that will be enormously powerful for those couples and their families waiting on pins and needles for the stability that attends to marriage and equal protection under the law.

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Jonathan Capehart is a member of the Post editorial board and writes about politics and social issues for the PostPartisan blog.