UPDATE: Senior GOP Source Responds to 'Hardball' Plan to Break Dems' Iran Filibuster

A senior Senate Republican leadership source reached out to discuss the case I laid out this morning concerning a possible path to breaking Democrats' Iran deal filibuster. He said Majority Leader McConnell will schedule another cloture vote early next week, likely on Tuesday. If and when that fails (assuming none of the 42 filibustering Democrats relent), GOP leadership is considering a number of options, including forcing votes on one or more highly-charged amendments related to the Iran deal. This maneuver would respond to Democrats' politicized posturing in kind, contriving scenarios in which filibuster-sustaining votes would be politically painful to cast, and could be used in future attack ads. The aide declined to provide details on the substance of these potential amendments.

As for whether upper chamber Republicans are girding for a bruising fight in which all Senate business is ground to a halt until Democrats cease their obstruction of an up-or-down Iran vote, the source demurred. Leadership is keen on moving other items to the floor in the coming weeks, including a ban on late-term abortions, as well as a government funding bill. With the clock ticking toward a potential partial government shutdown, the time frame for a protracted battle over what ultimately amounts to a symbolic vote is limited, he said. McConnell has stated repeatedly that Congressional Republicans will not allow another government shutdown, a move critics have blasted as preemptive disarmament. The aide also said that a key difference between the sex trafficking filibuster brawl Republicans won this spring and the current scenario is that Democratic members actually wanted to pass the trafficking legislation, whereas they've lined up against the Iran deal disapproval resolution.

Point taken, but I'd argue that obstructing an Iran vote is uniquely precarious for Democrats. The Senate voted 98-1 to demand a say over the deal, with yes votes coming from all 42 Senators who've now joined a filibuster to prevent their own legislative body from having that say. As I've detailed in my original post, the American people have turned sharply against the nuclear agreement, and a supermajority of voters believes Congress must approve of the deal before it's implemented. The House just voted against the deal by a

107-vote margin, with more than two dozen Democrats joining the opposition. It's true President Obama's power grab has guaranteed that his unilateral accord will go into effect without Congress' approval. But Senate Democrats have cynically decided to strip themselves of a vote on the matter altogether -- all to spare Obama the procedural humiliation of overruling the legislative branch's bipartisan rejection of his reckless policy. Democrats should be made to defend this unpopular stance, publicly and often. Their arguments are weak, and the public isn't inclined to buy their feeble talking points. Such a reckoning won't occur unless Republicans really force the issue, which unfortunately requires manufacturing some political theater to cut through the noise. Speeches, statements, and press availabilities won't suffice.

If GOP leadership is unwilling to exploit their control over the legislative agenda -- afforded to them by voters in 2014 -- in order to fight on an issue of enormous geopolitical and national security consequence, and on which they enjoy a substantial public opinion advantage, what is the point of having a majority? I'll leave you with Marco Rubio's take on Fox News earlier today. Spot on:

"We should be creative about doing everything possible -- if there was ever an issue on which we would stop everything to focus on something like a laser, it would be this. And instead, I get the sense that it's like, 'let's have a couple votes then let's move on to the next issue. This thing is done with.'"

Are Republican leaders interested in pursuing creative solutions here? A more instructive question, perhaps: How would Democratic leadership play their cards if the roles were reversed? Oh, and here's the White House's cavalier, childish attitude toward all of this. Laugh it up:

White House mocks Republicans again for scheming to prevent Iran deal, says it probably seemed like a good idea after a couple of margaritas
— Francesca Chambers (@fran_chambers) September 11, 2015