Ross Douthat: When Trump gets his alligator

If Watergate became, for Richard Nixon, a cancer on his presidency, then Donald Trump’s Ukraine scandal is shaping up as something different: It’s an alligator in his White House.The alligator, for readers who missed its recent moment in the news cycle, is the predatory beast that the president reportedly wanted to swim hungrily in a moat along our southern border, sharing the waters with poisonous snakes, shadowed by spiked-tipped walls above.But alligator mississippiensis is also a