Bloomberg is as insistent on order as Trump is on disorder, as steady as Trump is spastic. Trump won’t give us a moment’s peace. Bloomberg could lull us to sleep. Politically speaking, we need the R.E.M.s.

Bloomberg is as prepared as Trump was unready. The presidency for him wouldn’t be a first whirl at governance, some gee-whiz, why-not, how-hard-can-this-be lark. He spent 12 years, from 2002 through 2013, as New York’s mayor, in charge of a complicated city of more than 8 million people.

Trump operates by gut. Bloomberg demands data and more data. Trump doesn’t really have his hand on the wheel — he just wants to be the shiny hood ornament. Bloomberg is all pinpoint GPS navigation. He didn’t always steer New York in the right direction. But there was never any question that he’d keep us out of the ditch.