What’s the ‘nuclear option’? Senate stops everything to argue over obscure rules

Shown here are Senate Democratic Leader Harry Reid, left, and Senate Republican Leader Mitch McConnell. (AP)

The loudest, most-heated debate in Washington this week wasn't over immigration, skyrocketing student loan rates or even the uncertain fate of food stamps.

It was about rules.

As cries of "who cares?" erupt across the country, the Senate wonks in D.C. are actually taking this battle quite seriously. A showdown is set for Tuesday on what lawmakers call -- in all seriousness -- the "nuclear option."

Hyperbole aside, here is a primer on what the insular world of Washington is talking about:

At issue is the process the Senate uses to vote on nominees.

Democrats complain that Republicans are blocking a series of President Obama's appointments. Republicans say they've been plenty cooperative, and are only blocking in select cases.

But Senate Majority Leader Harry Reid, a Democrat, is threatening to potentially change the rules as early as next week so that majority Democrats could steamroll minority Republicans on these votes.

He has teed up a series of test votes for nominees on Tuesday. The threat is that if Republicans block them, Reid might use the "nuclear option."

This would mean he tries to change the Senate rules with a simple majority of just 51 senators, as opposed to the usual 67. Specifically, he would change the rules so that presidential nominations would no longer be subject to filibuster -- meaning they, too, could be approved with just 51 senators, as opposed to the usual 60.

Doing so would undermine the power of the minority party going forward.

This is something that Democrats warned about in apocalyptic terms when they were in the minority.

Now that Democrats are in control, Republicans are howling.

Senate Republican Leader Mitch McConnell said Thursday that Reid would go down as the worst Senate leader in history if he does this. He even suggested Reid would take this legacy to his grave.

"No majority leader wants written on his tombstone that he presided over the end of the Senate," McConnell said. "Well, if this majority leader caves to the fringes and lets this happen, I'm afraid that's exactly what they'll write."

Sen. John Thune, R-S.D., said "this is nothing more than a power grab."

Among the nominees in question are those for the National Labor Relations Board. A federal judge ruled recently that Obama's prior appointments to the board were invalid -- and Republicans have used that ruling to challenge the nominees.

But organized labor has been pushing Reid to change the rules to break the impasse. Some rank-and-file Democrats have also pushed for overhauling Senate procedures.

"Now what has happened is we find ourselves in the situation of a tyranny of the minority," Sen. Tom Udall, D-N.M., said.

Despite all the bluster, Reid might not be as well-positioned for this fight as Democrats make it sound.

He would still need 51 senators to change the rules. No Republican would support this, so he would be forced to draw votes from the 54 senators who caucus with Democrats.

And some long-time Senate Democrats, like Sen. Carl Levin, D-Mich., are known to be opposed.

FoxNews.com's Judson Berger and Fox News' Mike Emanuel and Kara Rowland contributed to this report.