The Senate held a key test vote on Wednesday on a bill that could move same-sex-marriage rights one step closer to protection under federal law. Democrats gained support from 12 Republicans, two above the threshold needed to overcome a filibuster. The bill’s progress reflects a shift in public opinion over time, with same-sex marriage now enjoying overwhelming support from Democrats and majority support from Republicans.

The public’s attitude toward same-sex marriage has been among the most significant shifts in American public opinion in recent decades. Seven in 10 American adults said in May of this year that marriage between same-sex couples should be recognized by the law, a record high according to Gallup. That represents a near complete reversal proportionally in the public’s views over the last 30 years. In 1996, when President Bill Clinton signed the Defense of Marriage Act, which defined marriage as between a man and a woman, nearly seven in 10 Americans said same-sex marriages should not be recognized by the law. Only about one-quarter said they should be valid.

Public support for same-sex marriage has grown since then. In 2004, when Massachusetts became the first state to begin issuing same-sex marriage licenses, 42 percent of Americans supported legalizing same-sex marriage. And by 2015, when the Supreme Court ruled in Obergefell v. Hodges that same-sex marriage was a constitutionally protected right, 58 percent of the public supported legal same-sex marriage.

Still, at the time of the 2015 ruling, just 30 percent of Republicans backed the change. Since then, support among Republicans has grown substantially, with a majority now in favor of same-sex marriage.