For supporters of gun regulations, a reckoning is here. Patrick Leahy, chairman of the U.S. Senate Judiciary Committee, released a package of gun legislation this week and plans hearings Feb. 28 on an assault weapons ban. A substantial majority of Americans supports universal criminal background checks for gun sales. Smaller majorities support a ban on assault weapons and on high-capacity magazines.

Yet while the politics of gun control have shifted in favor of regulation in recent weeks, they haven’t been upended. For new gun laws to get through Congress, they will almost certainly have to be less stringent than either reason or circumstance can justify.

A Senate group, including Democrats Charles Schumer of New York and Joe Manchin of West Virginia and Republicans Mark Kirk of Illinois and Tom Coburn of Oklahoma, appears close to a deal on legislation to expand criminal background checks to most private sales of guns. Perhaps as much as 40 percent of gun sales take place in the unregulated private market, enabling criminals to obtain lethal firepower without inconvenience or oversight.

The main sticking point among the senators is private record keeping. Coburn, whose gun-rights credentials can provide political cover to some of his less-assertive colleagues, resists requiring private sellers to maintain receipts of gun sales. Police officers say these receipts would come in handy when they’re tracing guns used in crimes. The National Rifle Association characterizes the measure as just one more assault on the Second Amendment.

So should gun-control proponents in the Senate give in on this one? If that’s the price of achieving near-universal criminal background checks, then yes. If ill-founded fears of gun-sale receipts leading to tyranny compel conservative legislators to abandon meaningful legislation, the cause of rational gun laws will be damaged.

Senators appear to have largely resolved privacy concerns. Prospective buyers wouldn’t have to disclose any information to sellers. Instead, they could upload their personal data to a secure website, where a background check would be promptly conducted. Perhaps once expanded background checks become law, supporters of gun regulation can then make the case for more comprehensive data collection. Meanwhile, they would do well to take the best deal in hand.

The massacre in Newtown, Connecticut, changed American politics; the consequences of lax gun laws became too horrifying to ignore. We support a ban on assault weapons and on high-capacity magazines, and we’re pleased that Leahy is moving to bring such proposals to a vote. But neither of these policies is as vital -- or seemingly as politically viable -- as a plan for comprehensive background checks.

The path to sensible gun laws will be long. Senate supporters must do whatever is necessary to pass a stronger background check law. The nation needs incremental progress, not magnificent failure.

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