5 tests for new WH Chief of Staff John Kelly

Steven Senne / AP

Booting Mooch was the easy part — hardly a fair fight for a four-star general.

Kelly is an almost perfect lab test of whether a Trump White House can be functional. He has all the ingredients to succeed: He's been granted unprecedented authority (for Trump), he's revered by all internally and has no dog in the factional wars in the West Wing. If he fails, we'll know this White House is truly ungovernable.

Here are five factors that'll help determine how the history books (and imagine how many there'll be!) treat White House Chief of Staff John Kelly: