Republican leaders on Capitol Hill are making no attempt to mask their fear, predicting that failure to pass a tax overhaul in the coming months will lead to a wipeout in next year's midterm elections. For the first time, some senators are contemplating whether their longstanding advantages could crumble amid a wave of primary challenges and other departures, putting their two-seat majority in jeopardy next year.
Particularly in the Senate, Republicans are increasingly mystified by their own grass roots, an electorate they thought they knew, and distressed that a wave of turnover in their ranks could fundamentally change the character of Congress. They fear that the inchoate populism that Mr. Trump personifies, and which Mr. Bannon is attempting to weaponize against incumbents, is on the march.
Mr. Trump is not helping. Speaking at a high-dollar fund-raiser for his re-election at Le Cirque restaurant in New York last week, Mr. Trump asked contributors what they would think if he worked with Democrats on health care, should Republicans prove unable to repeal the Affordable Care Act, according to a dinner attendee.