By Jordain Carney @ TheHill.com, Sept. 11

Top Senate Republicans are firing back at Stephen Bannon amid reports that he is eyeing primary challenges to GOP incumbents who he believes haven't been supportive of President Trump, calling on both the president and his ousted adviser to leave elected Republicans alone. 

"I wish they would focus on Democrats instead of Republicans," Sen. John Cornyn (Texas), the No. 2 Senate Republican, told reporters when asked about Bannon.

Sen. John Thune (S.D.), the No. 3 Senate Republican, added that the potential primary threats could make it harder for Republicans to hold onto their thin 52-seat majority despite a favorable 2018 map. 

"It does [make it harder]. And it's not particularly productive. ...We ought to stay focused on the task at hand," he told reporters. 

Sources told CNN and Politico that Bannon and his allies are actively preparing for Republican primary challenges to several sitting senators, including Sen. Jeff Flake (R-Ariz.) [....]