Yesterday, a group of African-American Democrats from Prince George's County, Maryland, endorsed Republican Lieutenant Governor Michael Steele, a fellow black, for the U.S. Senate. It might be the most important political development in the country this week. Control of the Senate appears to hinge on the results in one or two contests. There are no states in which Republicans have appeared likely to pick up a seat, although New Jersey remains a possibility. If Steele could manage an upset in the race for the seat of retiring Democratic Senator Paul Sarbanes, it could be the difference-maker. And Steele is undeniably...