CNN announced today that John King, anchor of its Sunday news program State of the Union, will anchor a new political news show starting next year in the 7 p.m. hour left vacated by Lou Dobbs. Dobbs announced yesterday that he is leaving CNN. Until King’s show launches, the network will fill the hour with a rotating cast of anchors on a program called CNN Tonight. King is perhaps best known for his role in CNN’s election coverage last year as the guy who analyzed results on a “Magic Wall” touch screen.