Rep. John A. Boehner and other House Republican leaders are huddling behind closed doors to draft a set of “principles” for immigration reform that they intend to unveil at their upcoming retreat on Jan. 29. Let me save them some time. There is one — and only one — principle for true immigration reform: Like any other public policy, it should serve the greatest interests of the greatest number of Americans. Clearly, very few if any public policies conform to that principle — hence, Congress‘ 8 percent job-approval rating — but few fail the test as thoroughly as our current...