Who knew? A billboard proclaiming that the Rev. Dr. Martin Luther King Jr. was a Republican has stirred a religious and political hornets' nest in Houston, where a church leader is trying to draw black voters into the Republican Party. The jumbo-sized roadside ad made its contentious claim for about a week -- until a local black activist charged that the sign unjustly politicized King's legacy and was hurting his community by telling a "blatant lie." "Martin Luther King may have very well believed in some of the Christian principles of the Republican Party, but Dr. Martin Luther King was...