Ross Douthat: When Trump gets his alligator

In this Oct. 3, 2018 photo, an alligator floats at dusk in the Davis Pond Diversion in Luling, La. (AP Photo/Gerald Herbert)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 useful condensed symbol of how the Trump administration has survived Trump’s own…