Netflix and Amazon have been nominated for hundreds of Emmys and Golden Globe awards in recent years, and that is a testament to both the quality of those companies and the transformation of television. But some of the credit is also due to “net neutrality,” the legal regime that nurtured and protected the open internet and streaming TV in the first place.

Streaming, after all, is a cheaper and better form of television. For that reason, it is something the cable industry would not have allowed to thrive had it been left to its own devices. Fortunately, net neutrality rules prevented cable companies from killing or interfering with streaming television during its infancy.

You might think it unwise, therefore, to question a policy that has yielded both lower prices and good television. But President Trump’s chairman of the Federal Communications Commission, Ajit Pai, on Wednesday announced plans to eliminate net neutrality (technically, make it “voluntary”) despite its popularity, record of success and acceptance by most of the industry.

His proposal is of dubious legality. But should it succeed, the only real winners will be the cable and phone industries, which will gain yet another way to raise prices for everyone. The proposal is the epitome of senseless government action and sharply out of step with Mr. Trump’s populist mandate. Did Trump voters really vote for higher cable bills?