Supreme Court Justice Samuel Alito, the devout Catholic conservative who has long warned of animus against religion in America, says in a new book that he believes the court's landmark decision extending marriage rights to same-sex couples was "perhaps the decisive point in our nation's turn against religious liberty."

Alito, who dissented sharply in the 2015 case, made the claim at Catholic University of America three years after Obergefell v Hodges in a speech that was not open to the public or widely covered at the time. The remarks were published this month in "So Ordered," a collection of Alito speeches that he says reflect his judicial philosophy and outlook on the country.