Democratic Sen. Tammy Duckworth is wading into the open primary to succeed longtime Sen. Dick Durbin, endorsing Lt. Gov. Juliana Stratton to join her in representing Illinois in the Senate.

Democratic Gov. JB Pritzker is expected to endorse his running mate, Lt. Gov. Juliana Stratton, for the U.S. Senate today, a move that could serve as a politically powerful warning to the rest of an emerging field seeking to replace retiring U.S. Sen. Dick Durbin.