Here’s a better question. Should the GOP filibuster the gun-control bill? Johnny Isakson says no:

“I’ll speak for myself on that question,” Isakson said on CBS’s “This Morning” when asked about the filibuster. “There’s no ambivalence on the gun issue, I think everyone knows what the issues are. We have not seen the final draft of the legislation that was produced, I understand, last night, but I think it deserves a vote up or down.”…

Isakson also said he could support a bill for universal background checks, depending on the language it contains.

McConnell, who does intend to filibuster, needs to hold 41 of the 45 members of his caucus to make it happen. Isakson is out; McCain said Sunday that he doesn’t understand the point of a filibuster here since Reid will allow amendments to the bill, so presumably he’s out too. Watch below and you’ll see that Rob Portman’s undecided. Presumably, since they have cover from senators from redder states to let the bill go forward, Susan Collins and Mark Kirk (and maybe Pat Toomey and Lisa Murkowski?) will also oppose a filibuster. If they do, and if Portman ends up opposing it too, that leaves a maximum of 40 Republican votes — not enough to stop the bill from proceeding to a final vote unless a few panicky Democrats from red states end up joining them. If you thought people like Mark Pryor and Mark Begich couldn’t sweat this issue any harder than they’re doing right now, think again.

But wait. Do we really want to stop this bill before a final vote? Maybe it’s in the GOP’s interest not to filibuster. Tom Maguire makes the case:

I’m with McCain – I don’t understand this Republican plan to filibuster Reid’s gun control bill (that would be DOA in the House anyway), thereby sparing a bunch of Red State Democratic Senators the dilemma of antagonizing either their Hollywood donors or their home state voters.

I suppose the filibustering group wants to be the NRA heroes that blocked the gun bill. Geez, couldn’t they be the heroes who let the Dems march off a cliff and (Here’s hoping!) gave the Senate back to the Republicans?

If you filibuster, you spare vulnerable Democrats who are up for reelection next year the sweatiest moment of all — an up-or-down final vote on the bill. You might very well get a united GOP caucus opposing that, which means it would take only six Democratic votes to kill the whole thing and utterly humiliate Obama. Worth a gamble? Besides Pryor and Begich, you’ve got a fair shot at getting Baucus, Landrieu, and Kay Hagan. Then you only need one more. Mark Warner? Jeanne Shaheen? Maybe Jay Rockefeller, who’s retiring? The odds are slim that Reid can’t hold 51 together in the name of not turning Obama’s gun-control push into a fiasco, but since, as Maguire says, the bill would almost certainly be DOA in the House, you have little to lose by making him try. In fact, if you’re worried about O using the “obstructionist Republicans” talking point to hurt the GOP next year, you could argue that it’s better to let the bill pass the Senate and then die in the House, since that complicates Obama’s message.

Exit question: Does McConnell even want Republicans to filibuster the bill? He’s voting to filibuster in order to protect his right flank ahead of his own reelection bid last year, but between Isakson, McCain, and Portman, there’s an unusual amount of public chatter from dissenters, which suggests McConnell isn’t straining hard against the idea within the caucus. Maybe he’s happy to let the bill go to a final vote for all the reasons above.

Update: Hard to believe this filibuster is happening.

Then again…