Davis, Callis set for fall showdown in Illinois
© Greg Nash

Rep. Rodney Davis (R-Ill.) has defeated attorney and former Miss America Erika Harold (R), ending the most serious primary threat to any Illinois lawmaker.

Davis will face establishment Democrats' favored candidate, former judge Ann Callis (D), who also won her primary Tuesday night. Callis, who had the backing of Sen. Dick DurbinRichard (Dick) Joseph DurbinTo succeed in Syria, Democrats should not resist Trump policy Hannity, Kimmel, Farrow among Time's '100 Most Influential' The Hill's Morning Report: 200 Days to the Election MORE (D-Ill.) and the Democratic Congressional Campaign Committee, was leading her more liberal primary opponent by a 30-point margin.

Davis is a top Democratic target this cycle — he won his 2012 race by less than 1 percentage point in the downstate Illinois swing district against a weak opponent. 

With 65 percent of precincts reporting, The Associated Press called the race for Davis, who was leading Harold by 57 percent to 38 percent. 

National Democrats celebrated Callis's victory and promised the downstate district would be competitive this fall. 

"Democrats across Illinois are strongly positioned to succeed in November because they are on the side of middle class families while their Republican opponents are stacking the deck for special interests," DCCC Chairman Steve Israel (D-N.Y.) said in a statement. "I especially congratulate Judge Ann Callis on her convincing primary win because she demonstrated her commonsense appeal and record of accomplishments like standing up for our veterans and families facing foreclosure."

Before he readied to face Callis, Davis first had to beat back his challenge from Harold. A Harvard-educated African-American former Republican National Convention speaker, she had an impressive biography to begin the race with. Harold also gained some national attention, making a few Fox News appearances and campaigning with Herman Cain.

But the freshman Davis outraised and outspent Harold by a wide margin in the primary, leveraging his strong ties to Republicans both in D.C. and Illinois from his days as a congressional staffer to freeze Harold out from any institutional support.

In other races, Marine reservist Larry Kaifesh (R) won his primary to face Rep. Tammy Duckworth (D-Ill.) despite spending from a super-PAC backing his primary opponent, and Illinois state Sen. Darlene Senger (R), the establishment favorite, narrowly won a four-candidate primary to face Rep. Bill FosterGeorge (Bill) William FosterStronger patents — better innovation — bigger economy We still need to march for science Protecting American innovation MORE (D-Ill.). Both Foster and Duckworth are favored in their Democratic-leaning suburban Chicago districts.

—This post was last updated at 11:20 p.m.