By preventing President Barack Obama from filling a Supreme Court vacancy, Senator Mitch McConnell secured Donald J. Trump the signature accomplishment of his young presidency: the confirmation of Justice Neil M. Gorsuch.
It was a strikingly public display of the growing distance and distrust between the president and his supposed Republican allies on Capitol Hill, one with major implications for navigating a complex set of obstacles the party faces next month, from keeping the government open to preventing a devastating fiscal default.
One Republican said it would be as if F.D.R. had undermined Eisenhower on the eve of D-Day. The unusual intramural conflict had the capital’s full attention even as the United States and North Korea traded warlike nuclear threats.