So when the president hosted a “news conference” in the Rose Garden with the president of Mexico on Wednesday, Mr. Reid thought maybe this time Mr. Obama would take questions. Instead, Mr. Obama allowed only a single question from the American news media, calling on a reporter from Univision, making it unlikely that he would be asked about Tuesday’s anti-incumbent election results. Sure enough, Mr. Obama was asked about the Arizona law aimed at stopping illegal immigrants, a law he had already denounced in his opening remarks and was happy to denounce again in response to the question. He did...