Here’s how the go-to guy works. Let’s say you’re a reporter on a deadline and you need a quote right this minute about how Republicans have rendered Congress dysfunctional. Well then, your go-to guy is Norman Ornstein​, a scholar at the American Enterprise Institute. Perhaps you want to give readers a little historical perspective, something eggheady about, say, how smoothly leaders of both parties used to work together before the lunatics (you know who they are) started running the asylum on Capitol Hill​? Quick: get “presidential historian” Douglas Brinkley on the phone before he goes live on the NewsHour! He’ll be sure to tell you, with a wistful air, that Tip O’Neill and President Reagan​ were always friends after five o’clock.

If it’s the economy you’re writing about, it’s Mark Zandi. He has all the qualities that go into making a go-to guy of the very first rank. He is fluent on television and keeps his sentences short. His demeanor is pleasant. He uses the word “narrative” with abandon—“narrative” being the hottest word in journalism since “transparency”; it’s this year’s “accountability.” And he’s a liberal. All go-to guys are liberals. They can’t be identified as such, lest their authority as disinterested observers be undermined and the reader or viewer begin to get ideas. Ideological fuzziness is good; ideological hermaphroditism is better…

In economics, Zandi is capable of meeting all of a reporter’s go-to-guy needs, so the trade has been careful in obscuring his liberalism. He is a registered Democrat, as he freely admits when asked. But he’s seldom asked. The key to his indispensability is that he once—once—did some work for a Republican. Early in the 2008 presidential campaign, one of John McCain’s economics advisors enlisted Zandi to file a weekly analysis of current economic data for the campaign’s use. He never advised McCain on matters of policy, he never met McCain, and he was never paid for his labor. The real payout, in fame and influence, came after the election.