Even as major Republican donors coalesced Wednesday around a last-ditch effort to halt Donald Trump's march toward the GOP presidential nomination, resignation was setting in among some onetime Trump critics. "It is too late," Republican media strategist Alex Castellanos, who had unsuccessfully urged top GOP contributors to back an anti-Trump campaign earlier in the cycle, wrote in an email. He went on: "If our self-indulgent Republican party establishment had really wanted to prevent a takeover of the GOP, they should not have gorged on political power while they failed to do anything to prevent the decline of the country. Our...