I haven't read Matt Bai's The Argument, though it seems, from the reviews, that the book's flaw was being conceived in 2004, reported in 2005, obviated in 2006, and released in 2007. That's not really Bai's fault. Lakoff really did seem like a big deal, and if you immersed yourself in the Democratic Party's search for messaging gurus, it's understandable that you'd ache for a bit of substance.
But that immersion is the key. The Democratic Party's reworking of its message was a prime Bai story over the last few years. His critique of it, by contrast, has been that Democrats need ideas, not gurus. Notably, that they need a social policy capable of withstanding the 21st century, the "information age," or whatever synonym we're using for The Now (zoom!) that week. But whatever the worth of the gurus, Bai's critique is myopic -- it's a function of what he's reporting on, rather than what's going on in the Party.
As a reporter, I focus on policy ideas. And damn it, I'm drowning. Bai seems to think Democrats need a health care plan, but I could show him no fewer than 20 fully-realized plans and outline the basic areas of consensus -- and they're broad -- that outline the Party's essential orientation on the issue. Same goes for pension planning, trade adjustment plans, or any and every other element of social policy you can think of.
These plans have a common thread -- a social policy for the 21st century, if you will: Globalization and its attendant economic forces have destabilized the working class and the corporate welfare state they relied on, so the government should step into the breach and guarantee what employers no longer can. And though Bai may not have been paying attention, Democrats have even settled on certain policy gurus -- notably Jacob Hacker, Joseph Stiglitz, and Elizabeth Warren -- who're uniting previously opposed wings of the party, as in Hacker's involvement with both the traditionally left wing EPI and they're bete noire, Robert Rubin's centrist Hamilton Project. Bai's book may be a good read, but if you only profile politicians and messaging types, you should have some self-awareness that you're unlikely to trip over much new policy thinking along the way, and an affirmative effort to search some out is required before you critique its absence.