My rule of thumb regarding tampering with the Senate’s filibuster rules, regardless of which party controls the chamber, is that it never happens. Like the real thing, the nuclear option in the Senate is best thought of as deterrence; when forced to deploy it, the party seeking to squash the minority inevitably caves. The prospect of their own annihilation when it inevitably winds up in the minority is enough to cool passions.

Mitch McConnell Sen. Mitch McConnell (Andrew Harrer/Bloomberg)

It was hardly a stunner then when Senate Democrats and Republicans reached a deal today to avoid the nuclear option. The Post reports: “The Senate dodged a constitutional showdown Tuesday with a bipartisan pact to confirm several nominees to run agencies overseeing Wall Street and labor relations, stopping the Democratic effort to change filibuster rules on a party-line vote that threatened to turn the chamber’s already chilled partisan tensions into a deep freeze.” It was pretty much a clean win for the GOP. (“Republicans won their demand for different Democratic nominees for the National Labor Relations Board, but gave assurances of a speedy confirmation that would make the board fully operational by next month.”)

As one senior GOP adviser put it, “They preserve the right to go nuclear; the GOP preserves the right to filibuster.” It did not go unnoticed that Majority Leader Harry Reid’s bluff had been called. The Associated Press observed:

Under the current proposal, Obama would drop efforts to win confirmation for two members of the National Labor Relations Board and name two replacements who would receive speedy consideration. Richard Griffin and Sharon Block were originally named to their posts as recess appointees, meaning they bypassed confirmation. An appeals court has since ruled their appointments were invalid, and the Supreme Court has agreed to review the case.

The proposed agreement would not resolve deep partisan divisions over the future use of filibusters to block a president’s executive nominees.  . . .  If ratified, the deal would mark a retreat by Reid from his insistence on Monday that Republicans promise not to filibuster future executive nominees.

I can imagine the announcement over the weekend that former Montana governor Brian Schweitzer (D) would not seek to replace Max Baucus, who is retiring, was a timely reminder: Today’s majority is tomorrow’s minority.