(Dolly Faibyshev | The New York Times) Former New York City Mayor Michael Bloomberg, a Democratic presidential candidate, at the Metropolitan Museum of Art’s Acquisitions Dinner in New York on Dec. 12, 2019. To choose Bloomberg as the alternative to Trump, then, is to bet that a chaotic, corrupt populist is a graver danger to what remains of the Republic than a grimly-competent plutocrat, writes Ross Douthat.