Finger-pointing between GOP establishment and Steve Bannon reflects rising concern about party’s prospects in midterms.

The upset defeat of Republican Roy Moore in Alabama’s special Senate election sparked finger-pointing Wednesday between the GOP establishment, who opposed Mr. Moore, and Donald Trump’s insurgent allies led by Steve Bannon, who backed him. The bickering set off by the victory of Democrat Doug Jones heightened anxieties about GOP prospects in the 2018 midterm elections, where Republicans will seek to hold onto their majorities in the U.S. Senate and House. “If we are to Make America Great Again for all Americans, Bannon must go!” said Rep. Peter King (R., N.Y.) on Twitter on Wednesday. For his part, Mr. Bannon is already eyeing 10 Republican primaries in which he has endorsed or might back insurgent candidates. That sets up intra-party fights that could extend deep into the 2018 midterm primaries in states that include Montana, Tennessee and Arizona.

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