Another Illinois Colleague Backs Kirk
Kirk, however, is expected to win the GOP nomination.
Until Tuesday, Johnson was one of two GOP Members in the delegation holding out on endorsing Kirk; Rep. Don Manzullo (R-Ill.) has said that has a policy not to pick sides in primaries.
“Mark Kirk shares my commitment to job creation, economic growth and care for our nation’s veterans,” Johnson said in a statement. “Mark will be a Senator we can all be proud of.”
CQ Politics currently rates this general election contest as a Tossup.