Senate Republicans will be deliberating over lunch Tuesday just how far to push one of the most politically risky filibusters they have contemplated in many years.

Guns hold such a unique spot in the political and cultural climate that it’s a tossup to predict that will happen. But assessing all the usually relevant factors leads to a pretty easy conclusion that the wiser course is to stand down and permit a wide-ranging debate on the legislation at hand.

Public opinion is solidly in favor of the background check expansion at the heart of the bill. Public opinion is even more overwhelmingly opposed to governance by obstructionism. President Barack Obama shows every sign of staying in the bully pulpit to pound on both those themes for as long as it takes. Eleven relatives of kids and teachers murdered at Sandy Hook Elementary have come to the Capitol, TV crews in tow, to rekindle the public’s outrage at those killings and to get in the faces of who would stop the debate before it even gets started.

There are also good tactical reasons for the GOP to permit a full-bore debate. It would create plenty of opportunity to force the five red-state Democrats running next year to cast no-easy-choice votes on a hot-button topic. And it would allow the Republicans to look magnanimous for permitting the legislative process to work as normal, while remaining confident that any gun control passed by the Senate faces dauntingly uphill prospects in the Republican-run House.

Beyond all that, there is the very real possibility a filibuster would be defeated. And that would underscore the notion that GOP leaders not only have little interest in their party’s ballyhooed efforts at rebranding and base-broadening but also are strategically incapable of leveraging the power of the National Rifle Association-fueled minority.

Only five Republicans will be required to break the filibuster if all 55 Democratic caucus members vote to at least bring the bill to the floor — which even the incumbents on the 2104 endangered list might do if they’re comfortable with their positioning on the substance of the amendments later on.  Johnny Isakson, John McCain, Lindsey Graham and Kelly Ayotte are already on record as saying the gun control proposals deserve an up-or-down vote. Mark S. Kirk and Patrick J. Toomey are key to bipartisan negotiations on background checks and presumably want the fruits of their labors to get a hearing.

In theory, other backers of a full-fledged debate would be the five Republicans who remain 14 years after voting for the last major gun control package passed by the Senate. Thad Cochran, Susan Collins, Orrin G. Hatch and Jeff Sessions all voted for expanding federal background checks to cover customers at most gun shows, banning imports of high-capacity ammunition clips and requiring childproofing hardware for all handguns, It was part of a crime control package that won 73 Senate votes in the months after the Columbine High School massacre, but then died in the GOP House.

The other Republican “yes” vote remaining from 1999 is Mitch McConnell. Now he says he’s standing with at least 13 other Republicans who would be willing to talk around-the-clock to kill a somewhat similar gun control bill in the cradle.

The others in the group are McConnell’s fellow Kentuckian Rand Paul, Dan Coats of Indiana, Ted Cruz of Texas, Mike Lee of Utah, James M. Inhofe of Oklahoma, Richard M. Burr of North Carolina, Michael B. Enzi of Wyoming, Marco Rubio of Florida, Ron Johnson of Wisconsin, Jerry Moran and Pat Roberts of Kansas, and Michael D. Crapo and Jim Risch of Idaho.

McConnell, who’s already got $8.6 million on hand for his 2014 campaign in Kentucky, seems to have decided for now that he’s more wary of a challenge from his right than from his left next year. Whether he sticks with those conservative hardliners or works to steer that group to a different posture in the next couple of days could be one of the bigger tests of his tenure as floor leader.