Marco Rubio and Ted Cruz, back from the campaign trail, have something productive to do in Washington. They’ve taken the lead against President Obama’s plan to give up U.S. protection of the open Internet. The Obama administration announced in 2014 it would end U.S. oversight by canceling the Commerce Department’s long-standing contract with the Internet Corporation for Assigned Names and Numbers, or Icann. Despite enormous effort over the past two years by the multi-stakeholder community of network engineers and developers, no one found an alternative to U.S. stewardship that would protect the global Internet from censorship by authoritarian regimes. The...