The background-check amendment offered by Sens. Pat Toomey and Joe Manchin was too vague for law-abiding citizens to understand with certainty, and too easy for criminals to avoid. The plan created more questions than it answered about which types of transfers are lawful without a background check and might ensnare law-abiding gun owners simply exercising their constitutional rights. It also left in place a number of gaps that could easily be exploited by criminals intent on obtaining guns.

The Toomey-Manchin amendment admirably attempted to carve out certain protections for gun owners, but today’s carve-outs are tomorrow’s loopholes. The current “gun show loophole” was itself once considered a legitimate carve-out that protected certain private sales.

The amendment also took an incremental step toward universal background checks, which, as a Justice Department memo written earlier this year suggested, are effective only when coupled with a national registration system. Admittedly, the Toomey-Manchin plan prohibited a national registry. Yet it required a massive expansion of gun ownership data collected by federally licensed dealers to which the government has access.