Two longshot efforts to alter the Republican Party’s official position on same-sex marriage failed Tuesday morning. Republicans drafting the party’s platform in Tampa rejected the pair of amendments, but each found some support among the delegates. The first, proposed by Rhode Island delegate Barbara Fenton, called for ending government-recognized marriage and replacing it with civil unions for both homosexual and heterosexual couples. ... Family Research Council President Tony Perkins, a delegate from Louisiana, opposed the measure. “This would move us away from a party that recognizes the benefits that marriage extends to a society,” Mr. Perkins said. “We recognize nature,...