Republicans are talking about repeal-and-replace as “three pronged”—pass the current House bill, deregulation through Mr. Price’s executive action, and then measures that can later be attached to must-pass bills. Mr. Price’s letter is the beginning of prong two.

Republicans have an obligation to try to revitalize insurance markets, and not only because Americans depend on coverage. Repealing and replacing ObamaCare is also an opportunity to show that conservative ideas can work in health care. The reason the opposition is so furious is that liberals fear they might succeed.

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