Democratic leaders increasingly describe themselves as the “big-tent party.” Gavin Newsom , the apotheosis of a political chameleon, has argued for a Democratic coalition stretching “from Manchin to Mamdani.  Senate Minority leader Chuck Schumer calls the party’s big tent “a strength, not a weakness,” and Democratic National Committee Chairman Ken Martin has described a coalition encompassing “conservatives, centrists, progressives and leftists.”

I wonder why he didn’t mention communists because if you read between the lines of the DSA’s platform – that’s precisely the path the DSA is following.

Every successful political party needs a big tent.  But a tent without boundaries isn’t a political philosophy, it’s a euphemism that’s used when a political party is unwilling or unable to police its own ideological boundaries.

Democrat leaders tell us they can accommodate the democratic socialists without surrendering control to it.  Really?  Political movements have a way of outgrowing their sponsors.  The danger isn’t simply that the Democratic Party has allowed the camel to poke its nose into the tent.  It’s that the camel soon decides he’s bigger and stronger than the Bedouin who opened the tent flap in the first place.

Political parties are coalitions, and ideological disagreement is hardly unique – that’s politics.  But a problem occurs when a party’s leadership becomes more fearful of its ideological fringe than the fringe is fearful of the party’s leadership.

A relatively small but intensely motivated faction doesn’t have to represent a majority of Democratic voters to exercise disproportionate influence.  Activists organize demonstrations, provide campaign volunteers, raise money, dominate social media and, most importantly, vote in primaries.

But they also threaten establishment democrats with primary challenges.  And when that happens, instead of asking, “What do my constituents believe?” an elected Democrat must also ask, “What happens to me if I cross the activists?”

Jonathan Turley has written about what he sees as the increasing unwillingness of Democratic politicians and institutions to confront elements of their activist left.  Turley’s “staying ahead of the mob” analogy describes the political dynamic particularly well.

Nobody has to order politicians to move left.  They move because doing so becomes the path of least resistance. Yesterday’s radical proposal becomes today’s position and eventually tomorrow’s loyalty test.  Once party leaders accommodate a position to maintain coalition unity, retreat becomes almost impossible.   And a democrat who questions the mob risks being accused not merely of disagreement but betrayal.

America writ large doesn’t vote like Brooklyn, Minneapolis, San Francisco and other overwhelmingly Democratic jurisdictions.  A democratic socialist representing a district Democrats routinely win by enormous margins can advocate positions carrying virtually no electoral penalty at home.  But Democrats running in Pennsylvania, Michigan, Wisconsin, Arizona or in other competitive congressional districts inherit the national party’s image whether they want it or not.

Republicans don’t have to prove every Democrat embraces every progressive position.  They merely have to put the most provocative statements of prominent Democrats into campaign advertisements and ask one question, “Is this your Democratic Party?”

That is how a relatively small ideological faction can become the public face of a much larger political coalition.  Longtime Democratic strategist James Carville recognizes the danger. While other Democratic leaders talk about making the tent larger, Carville argues there comes a point when a political party has to determine what it stands for—and what it doesn’t

And that’s the distinction the democrats have yet to confront.  A genuine big tent accommodates disagreement.  Democrats can disagree about taxes, immigration, abortion, policing, Israel, climate policy and the appropriate size of government while remaining Democrats.

But every political party ultimately has boundaries.  Otherwise “big tent” becomes “We are unwilling to tell any important constituency that it has gone too far.”

It’s easy to understand the thinking.  Keeping democratic socialists inside the Democrat Party may be preferable to driving them into a third party that splits the Democratic vote.  The republicans don’t have that problem even with its populist wing, because it’s nowhere near as radical as the DSA.  Nonetheless, coalition politics inevitably requires compromise.

But compromise works only when influence runs both directions.  If the establishment repeatedly accommodates the insurgents while the insurgents increasingly dictate the terms of accommodation, the relationship is fundamentally flawed.

Initially, an insurgent movement needs the established party.  The party possesses ballot access, campaign infrastructure, donors, elected officials and institutional legitimacy.  But every primary victory shifts that balance.  Eventually the insurgents aren’t asking the establishment to let them into the Democrat Party.  They’re competing to determine what the Democrat Party is.

And that’s the real danger confronting the democrats.  The problem isn’t a far-left wing.  Every successful political party contains factions.  The danger comes when party leaders lack the courage to tell that faction, “No you don’t belong!”

Eventually “big tent” stops describing ideological tolerance and starts describing political surrender.  And at that point the question is no longer how large the Democratic Party’s tent should be.  The question becomes: Who controls the tent?