Just how much fallout will Majority Leader Harry Reid’s deployment of the “nuclear option” have for the Senate?

That will be the key question when the Senate returns from what’s scheduled to be a two-week recess for Thanksgiving and Hanukkah. The Nevada Democrat said he was left with no choice but to effectively change the rules with a simple majority vote after Republicans filibustered three consecutive nominees by President Barack Obama to the U.S. Court of Appeals for the D.C. Circuit — positions some Republicans argue shouldn’t exist at the moment.

The move means Obama will be able to get high-profile nominations and judgeships approved at least through the midterm elections. But Reid surely knows that the wildly controversial move invites a retaliatory response from Senate Republicans, though they’ve thus far demurred from identifying exactly what they may do.

“I don’t think this is a time to be talking about the reprisal,” Minority Leader Mitch McConnell told reporters shortly after the procedural votes that enshrined the “nuclear” maneuver in the Senate’s precedents. “I think it’s a time to be sad about what’s been done to the United States Senate, the greatest deliberative body in the world.”

What the Kentucky Republican said next sheds some light onto why the retaliatory strike might be neither obvious nor proportional.

“There’s a lot of nervousness on the Democratic side. They’re in a panic about Obamacare. The majority leader desperately tried to change the subject,” McConnell said. “We want to get back on the subject. For most Americans, what they’re thinking about right now is they’re losing their health insurance. Their premiums are going up. Jobs are being lost. And we need to talk about what the American people are most concerned about.”

If Senate Republicans want to see the focus back on health care, trying to shut down the Senate with retaliatory tactics would seem counterproductive. And going overboard on retaliation might only invite Reid to clamp down even more on the rules to boot.

During the previous nuclear standoff in July, Sen. Lamar Alexander warned Democrats that Republicans would take the case to the voters, arguing that in a future Senate, they could use the same procedural tactic to do away with supermajority requirements to overcome legislative filibusters.

“It will turn this into a national debate about who controls the new majority institution in our country, because we’ll have a new one for the first time in 230 years, the United States Senate, and we Republicans want to be able to do with 51 votes whatever we can think of to do, any day we want to do it,” the Tennessee Republican said, noting his wish list would include repealing Obamacare and opening the Yucca Mountain nuclear repository.

Asked about his next move, Alexander — who helped negotiate the way out of the July rules change threat — said, “I’m going to start by reminding the American people the election is the cure for this problem.”

For his part, Reid dismissed the idea that changing the rules of the game raised the stakes for the midterms.

“If you look around the country, we’re doing pretty well,” Reid said in reference to the 2014 map, before saying of the move to curtail filibusters of nominees: “This won’t be much of a story in a week or two.”

Reid appeared at peace with his decision Monday in an interview with NPR, while acknowledging that at some point the filibuster may end entirely, and not just for nominations.

“If some future leader decides that’s what they want to do, then they can have a vote before the full Senate and decide if that’s what they want to do,” Reid said. “The Senate is a democratic body; it always has been. We work on collegiality just like judges do. But there comes a time when collegiality breaks down and you have to do something.”

That said, Republicans will have no shortage of opportunities to throw wrenches into the works. It still takes 60 votes to invoke cloture on legislative business. And the deployment of the “nuclear” option didn’t wipe away the time hurdles for confirming nominations — it just changed the vote threshold to a simple majority for all the nominations short of the Supreme Court.

That means it still won’t be feasible for Reid to go through the cloture process to confirm every routine nominee, meaning that blanket holds like the one floated by South Carolina Republican Sen. Lindsey Graham over the investigation of the attack in Benghazi, Libya, would remain relevant.

Any senator could also force formal approval of the previous day’s proceedings and prevent committees from conducting business past the first two hours of the day.

Judiciary Chairman Patrick J. Leahy also has not changed his policy of stringent adherence to the committee’s “blue slip” practice, which requires both senators from a home state to return a slip allowing the committee to consider the nominee.

“I assume no one will abuse the blue-slip process like some have abused the use of the filibuster to block judicial nominees on the floor of the Senate,” the Vermont Democrat said in a statement, suggesting that changes would come only if abuse arises.

The most widely publicized blue-slip problem in recent years involved Reid and Nevada Republican Sen. Dean Heller. Heller blocked the advancement of Elissa Cadish to be a federal judge in Nevada, a nominee favored by Reid, citing concerns with her views on the Second Amendment.

The first big test may come with the fate of the fiscal 2014 defense authorization bill, which would need an expedited process to enactment. Armed Services Chairman Carl Levin reminded reporters last week that wouldn’t be a first.

“One year we did this by unanimous consent on the last day of the session, so I’m far from giving up, believe me,” the Michigan Democrat said after the Senate rejected a bid by Reid to limit debate.