With the decision by Attorney General Beau Biden (D) not to run, the Crystal Ball has just changed its rating on the Delaware Senate race from Toss-Up to Leans Republican. Congressman Mike Castle (R) is now the favorite to win the seat of interim Sen. Ted Kaufman, formerly held by Vice President Joe Biden. This is more good news for Republicans on the Senate front. Delaware is normally a Democratic state, but it has consistently backed Mike Castle through two gubernatorial terms and nine terms in the U.S. House. A moderate Republican, Castle will be 71 by the time of the election, suggesting that he may serve only the four years remaining in Joe Biden’s term. Beau Biden may have such a scenario in mind, with 2014 as his next Senate target date. The Democratic nominee will be New Castle county executive Chris Coons. While not nearly as well known as Castle, Coons is an acceptable Democratic candidate. At this point, we have made the seat “leans R” rather than “likely R” because we remember when a little-known local politician named Joe Biden upset the odds-makers in 1972, coming from way back to defeat incumbent GOP senator (and former governor) J. Caleb Boggs—even while President Nixon was winning the state handily. Delaware is a state where personal campaigning matters enormously. It is small enough so that a challenger always has a shot, especially given the strong Democratic base in Wilmington.