The Senate isn’t serious about enforcing the nation’s immigration laws. It is bad enough that the bill that 39 Democrats and 23 Republicans just voted to pass provides an amnesty to illegal immigrants already here. There might be an argument for doing that if there were any evidence of a commitment to enforce the immigration laws in the future. But the bill actually prohibits local police from enforcing civil violations of immigration laws—which in practice, given the byzantine rules distinguishing between civil and criminal violations of those laws, will get local police out of the enforcement business altogether. No serious...