KENILWORTH—Five-term North Shore Rep. Mark Kirk formally announced his bid for the Republican nomination for the U.S. Senate today, billing himself as an independent who wants to lead others who are “not afraid to stand alone” against the corruption that has infiltrated Illinois politics. Standing in front of his late father’s north suburban home, Kirk said his record as a moderate on social issues shows he is “not an ideologue or party partisan.” . . . . . Kirk listed as endorsers Sen. John Cornyn of Texas, who heads the Republican National Senatorial Committee, as well as GOP Sens. Mitch...