Yeah, he's at it again. Fortunately, Ed Kilgore is too, quickly debunking Matt Bai's latest.
The one thing that I'd emphasize that Kilgore doesn't really talk about: Congressional party leadership contests are rarely decided on ideology. They just aren't. Yes, Nancy Pelosi is almost certainly more liberal in her position as Member of the House than Steny Hoyer (although it's anyone's guess whether that's a matter of their deepest convictions or their constituencies), but Speaker Pelosi -- or, now, Minority Leader Pelosi -- isn't going to be significantly more liberal than Minority Leader Hoyer. To hold that job, one has to keep the House Democratic Caucus happy, and what's going to keep the bulk of the House Democratic Caucus happy (on ideology) is being a mainstream liberal. Anyone who wants the job will rapidly adjust their issue positions to match.
What really determines these sorts of elections is internal caucus stuff: is the Speaker (or Minority Leader) good at balancing committee action with party leadership influence; is she a good strategist; does she protect Members from tough votes as much as possible; is she a good fundraiser; and then a whole lot of interpersonal stuff, everything from whether the candidate gets along well with the caucus to scheduling. All that, plus plenty of called in favors and logrolling.
Every time these leadership transitions come up, much of the press treats them as proxies for some larger battle. They relegate quotations from actual Congressional insiders about how it's actually about which candidate delivered a good parking space or delivered on a family-friendly schedule or allowed a Member to cast a key vote against some important bill because she secured enough votes elsewhere to the bottom of the story, and treat them as quaint little sidebar anecdotes. They're not. Those anecdotes are the real story; ideology is usually (sorry) a red herring.