Every politician claims to hate fraud in government, and the House of Representatives will have a chance to prove it Wednesday when it votes to close a gigantic hole for potential abuse in the Affordable Care Act.

The Health and Human Services Department announced in July that it won't verify individual eligibility for the tens of billions in insurance subsidies the law will dole out. Americans are supposed to receive those subsidies based on income and only if their employer doesn't provide federally approved health benefits....