What’s the “shadow party”? Joe Biden should probably find out.

Twenty-one years ago, John Judis and Ruy Teixeira wrote a book that defined a political era.

In “The Emerging Democratic Majority,” Judis and Teixeira argued that America’s demographic destiny belonged to the Democrats.

A left-of-center coalition of minorities, young people, women, and knowledge economy professionals was going to allow the Dems to break through the political stalemate that defined the early 2000s and perhaps even create an FDR-style realignment.

Two years after the book’s publication, in 2004, Barack Obama was elected to the Senate from Illinois and he seemed to be the perfect avatar for this new Democratic majority.

In 2008, Obama put together the very coalition that Judis and Teixeira described in their book and he won the White House. Democratic strategists pointed to the Judis-Teixeira theory and confidently predicted that their party now had a lock on the Electoral College.

Then, Doanld Trump came along and picked the lock.

Now, Judis and Teixeira are back with their explanation about what happened.

And their new book, “Where Have All the Democrats Gone?”, is not likely to be embraced so warmly by the party that they both say they want to succeed.

“Democrats,” they write, “need to look in the mirror and examine the extent to which their own failures contributed to the rise of the most toxic tendencies on the right.”

John Judis and Ruy Teixeira have been important intellectuals in many of the left’s prestige institutions: The New Republic, the Center for American Progress, and the Brookings Institution just to name a few.

But in their latest book, Judis and Teixeira point to two culprits that, despite the electoral successes of the Biden era, they believe are crippling the Democrats’ long-term potential.

One, is pro-Wall Street, pro-Silicon Valley economic policies embraced by Bill Clinton, Obama and other party elites for decades.

And two is what they call the cultural radicalism of the modern progressive movement, which they dub the “shadow party,” and that they argue is alienating working class voters on four key issues: race, immigration, transgender rights, and climate.

In perhaps the most controversial chapters of the book, they argue that on those four issues Democrats should be occupying a middle ground somewhere between Trump and the far left, but instead have been pushed to the extremes by the activists of the so-called shadow party.

This is a book that reads like worthy but innocuous political history in its early chapters but by the end is pouring gasoline on the ideological fires that have been burning among progressives and moderates ever since the 2016 Democratic primaries.

And it is now causing a firestorm of debate and criticism among politicians, pundits, strategists, and thinkers on the left.

Playbook co-author and Deep Dive host Ryan Lizza recently caught-up with Judis and Teixeira to ask them: Where have all the Democrats gone? And what does this mean for 2024?