Three national trends could conspire to give socialists widespread electoral and policy success:

1. We live in age of movements, not parties. National Democrats are terrified of the rise of Ocasio-Cortez, and for good reason. They may not have any more influence over the socialist surge than Republicans had over Donald Trump’s rise in 2016. Trump broke through Republican “establishment” opposition as if it didn’t exist — because it didn’t. Today’s national parties are event planners for movements. Parties belong to movements more than movements belong to parties. Movements like the Tea Party, and now Democratic socialism, have supplanted party structures as organizers of ideas and debate.

As a longtime aide to U.S. Rep. and then-Sen. Tom Coburn, I can testify to the fact that confronting entrenched power was not mere theory. In fight after fight — especially our successful campaign to eliminate congressional earmarks — we experienced the overwhelming strength of grassroots movements and weakness of national party structures.

Joe Lieberman, the Democratic nominee for vice president in 2000, is right to warn that Ocasio-Cortez’s policies could bankrupt America, but today’s Democratic Party left Lieberman long ago. Today’s Democrats lack the credibility and political power to stop the socialist surge.