Today, Rhode Island’s state Senate will vote on a bill to legalize same-sex marriage. The bill has already passed the House of Representatives and is widely expected to pass the Senate, after which it will go to Governor Lincoln Chafee, who supports the bill, for signature. Same-sex marriage is coming to Rhode Island. And it's coming despite the fact that the president, majority leader and Judiciary Committee chairman in Rhode Island’s state Senate all oppose same-sex marriage and could have stopped it from coming to a vote.

These opponents gave up because they fear the electoral power of same-sex marriage supporters. One Democrat who was against marriage equality lost a primary in 2012; others won but didn't want to face similar challenges in 2014. WPRI-TV’s Dan McGowan and Ted Nesi report:

"Last year's elections saw FightBackRI, a well-funded and highly organized political action committee, target lawmakers who were opposed to same-sex marriage. The group focused its efforts on the Senate because it was confident the bill would pass in the House, where openly gay Speaker Gordon Fox is a longtime proponent of the measure.

"FightBackRI's most high-profile challenge was against Judiciary Committee Chairman Michael McCaffrey, D-Warwick, who fought off Laura Pisaturo in the toughest re-election fight of his two-decade career. While the results at the polls were mixed for the group, the challenges represented a shot across the bow at incumbent Democrats -- and a sign gay-marriage supporters were unlikely to give up."

This is similar to what happened in New York in 2011: passing gay marriage depended not only on four Republican state senators voting yes but also on Dean Skelos, the Senate’s Republican presiding officer, agreeing to let gay marriage come to the floor even though he opposed it. Rhode Island and New York are both examples of the “no fingerprints” strategy for gay-marriage opponents: letting it become law while taking as little credit or blame as possible.

If the Supreme Court doesn’t intervene, this will be a key political theme over the next 20 years: gay marriage opponents strategically acquiescing so they can stop fighting a fight they know is doomed and electorally costly. Rhode Island’s topsy-turvy politics mean that the officials making that calculation today are Democrats (all five Republicans in Rhode Island’s state Senate support marriage equality), but in most states, it will be Republicans who search for ways to lose gracefully on the issue.

(Josh Barro is lead writer for the Ticker. Follow him on Twitter.)