President Obama, whose last noteworthy statement on same-sex marriage was that his views are “evolving,’’ came out in favor of it Wednesday in a televised interview. The sudden interview comes after statements by Vice President Joe Biden on Sunday were widely interpreted as an endorsement of gay marriage. On Monday Education Secretary Arne Duncan said he believes same-sex couples should have the legal right to marry, and on Tuesday voters in North Carolina approved a constitutional amendment banning gay marriage.