The details of the Senate Finance Committee’s hush-hush health talks aren’t fully known, but leaks suggest that one all-but-certain highlight will be new federally created health “cooperatives” to compete against private insurers. The onus is on Republican negotiators Chuck Grassley and Mike Enzi to explain why this isn’t merely the House “public option” in a better suit.

North Dakota Democrat Kent Conrad floated the co-op concept last month, to attract Republicans who oppose President Obama’s state-run plan. According to Mr. Conrad, these nonprofits—modeled on local electricity or rural farm co-ops—fulfill the liberal goal of competing against private insurers, yet avoid “government control,” since they will be member-owned. Presto, a Beltway splitting of the political baby.

And in theory, health-care co-ops needn’t be destructive.[...] But the Senate is talking about government-sponsored co-ops, and that means multiple devils are in the details...