As I type, the incoming Republican majority in the chamber will have at ... curtail some of their party’s most radical instincts. If there are, say, 54 Senate Republicans, the party’s far-right will be able to do whatever it wants.

After picking up seats in West Virginia, Ohio and Montana and winning an unexpectedly close race in Nebraska, the G.O.P. sealed a majority. Tight races in swing states will determine their margin.