The paragraph is followed by an incomplete phrase or sentence which summarizes the main idea of the paragraph. Choose the missing words of the phrase or sentence.

Gay marriage is to become legal in England and Wales after the lower house of the British parliament approved the final changes to a law that had Prime Minister David Cameron's backing. Last month, the U.S. Supreme Court delivered a landmark victory for gay rights by forcing the federal government to recognize same-sex marriages.
Gay marriage gaining legal（）