SNIP For nearly a decade now, Piker, who streams under the name HasanAbi, has been one of the most famous political commentators in America. If you’re a certain type of mainstream liberal—or a not-very-online moderate or conservative, for that matter—you may not have heard of him. His precise class of celebrity is difficult to describe, but in some respects, he has inherited the role of the agenda-setting television pundit for a generation that ditched the traditional medium long ago, if it ever knew it at all. Piker streams every day, weekends and holidays included. Outside of a few bathroom breaks,...