The state's ban treated "gay and lesbian persons differently in a way that demeans them," U.S. District Judge John G. Heyburn wrote Wednesday. While the case dealt with out-of-state marriages, it does not require the state to perform same-sex marriages.
Heyburn cited a long line of cases going back to the legalization of mixed-race marriages and mentioned recent same-sex marriage decisions in nine other states, including Hawaii and Utah. But he mainly relied on the U.S. Supreme Court's 2013 ruling striking down a section of the federal Defense of Marriage Act, on which Kentucky's same-sex marriage amendment had been based.
The judge also pointed to older rulings dealing with race and gender, noting that bans on interracial marriage, segregation and restrictions on women had been cited in the past as keys to a more stable society. But courts gradually did away with those restrictions.
"Each of these small steps has led to this place and this time, where the right of same-sex spouses to state-conferred benefits of marriage is virtually compelled," wrote Heyburn, who took a seat on the federal bench in 1992 after being appointed by President George H.W. Bush with the backing of U.S. Sen. Mitch McConnell, both Republicans.
The ruling comes on the heels of decisions by federal judges in Utah and Oklahoma that struck down gay marriage bans in those socially conservative states. A case is also awaiting a federal judge's decision in Virginia. A victory there would give gay marriage supporters their first foothold in the South.