Human beings are masters of rationalization. And over the past ten days, several hundred of those humans have repeatedly cast votes leading inevitably to a shutdown of the government. So how are those votes rationalized? We've identified some of the top contenders. (Unless otherwise identified, all examples below are from members of Congress.)

Theory #1: Republicans are just trying to negotiate a deal.

Examples:

Problems with the theory: Generally, negotiations over transactions are about finding mutually agreeable terms to change the status quo: a buyer makes an offer on a house, if the seller thinks it's too low, she can not sell. In Congress, the theory is that by negotiating the competing interests among elected representatives will benefit the broader public. Nearly every bill that passes includes such negotiation: bills are amended to incorporate concerns of legislators in order to secure their votes of support. That happens even when bills pass on party line votes. It's how representative democracy is intended to work. But negotiation requires a give-and-take. We'll approve this amendment in exchange for your vote. That's how it works in the rest of the world, too. You want this car? Well, what'll you give me for it?

Which prompts the question: What are Democrats getting from the "negotiation" the Republicans above offer? Hint: "A functioning government" doesn't count unless there is an implicit willingness to have a non-functioning government (i.e. you don't get the car if the offered price is too low). If the GOP was suggesting that they might trade a delay of Obamacare for, say, expanded background checks on gun purchases — that's a negotiation. A "negotiation" of the sort in which the choice is between a bad thing happening and someone giving up something of value to them is the sort of negotiating that kidnappers employ. Or big brothers who offer to release you from a headlock in exchange for your dessert. Why won't Harry Reid negotiate when he's going to give up his dessert?

Theory #2: This is a protest over a dire issue.

Examples:

Roy is Sen. Ted Cruz's Chief of Staff.

Problems with the theory: The advent of the Tea Party in the wake of Obama's election provided a voice for the far-right of conservative politics. And they had tons of rallies and protests and all the other hallmarks of a burgeoning political movement. By 2010, the Tea Party was electing representatives to Congress. And here in 2013, they've got a sizeable, informal caucus. The traditionalists in us would note that there's a difference between being an activist and being a legislator. The latter, representing more than that vocal base, is tasked with resolving problems, not just railing against them. Congress has always had its gadflies, but with the Tea Party legislators, we now have a swarm.

What primarily undermines this theory isn't simply that this is behavior unbecoming of an elected official. Instead, the problem is that politically-motivated obstructionism was the strategy of the Republican caucus at large since the beginning of the year. On Monday, New York's Jonathan Chait outlined the "Williamsburg Accord," an agreement stemming from a caucus meeting in January that was approved by leadership to provide exactly the sort of tension that is now obvious. In other words, this isn't the Tea Party swarm, motivated by the base, taking up arms against a Socialist Obamacare under the mantra "Don't Blink." This was always the plan.

But the biggest problem with thinking of the shutdown as protest is that, unlike, say, a sit-in at college cafeteria or a product boycott or even a general strike, there are very few rank-and-file Tea Partiers who are embracing the shutdown as a method to change a dire policy. The shutdown is, instead, being discussed as a regrettable thing that's the other guy's fault. 

Theory #3: This is retaking the Senate in 2014.

Examples:

Walsh worked as a strategist for Sen. John Cornyn of Texas.

Problems with the theory: Let's state at the outset that this theory is perhaps the strongest of the bunch. Over the course of three votes, the House Republicans got Senate Democrats on record as opposing a delay to Obamacare, supporting a tax on medical devices, endorsing employer-subsidized contraception, and opposing eliminating the government's co-pay for Congress' insurance. As Salon's Brian Beutler put it, Boehner was able to "force Dems to take tons of easily spun votes." In heavily Democratic states, these votes wouldn't matter. But Arkansas voters might be less lenient with Mark Pryor in 2014 after he voted for a tax and mandating contraception coverage on the same day. The truth isn't that simple, of course, but attack ads aren't known for nuance and complexity.

The main problem with the theory is that it appears to be largely emergent. Boehner could easily have pushed for one vote on all of the issues and achieved the same result. And it wouldn't have prevented him from pushing for a non-amended funding resolution on Monday after the show votes — a measure that would have easily passed the House with Democratic support. This is not an overarching theory explaining why Republicans got into the situation, but it may explain how the party is salvaging something from it.

Theory #4: Republicans are resorting to extortion.

Examples: Contrast comments by Ted Cruz on CNBC on Monday — “Everyone agrees that the debt ceiling is going to be raised" — and from Boehner spokesperson Brendan Buck — "No one is threatening to default" — with the extensive list of demands offered by the House Republican caucus last week as trade-offs for that inevitable debt ceiling increase.

Problems with the theory: There aren't many problems with the theory. Instead, there are problems with the practice. "I've got this thing, and it's fucking golden," said former Illinois governor Rod Blagojevich in the aftermath of Obama's election in 2008. "I'm not just giving it up for fucking nothing." He was empowered to appoint the state's next senator, and he wanted to see what he could get for it. He's now in prison, convicted of extortion. That's the extreme, of course. But the parallels here are enough to make anyone wary.

In that CNBC appearance, Cruz went on, as reported by the National Review. "The question is whether Harry Reid and the president will maintain the same negotiating position they have on the continuing resolution, which is we will bargain for nothing, give us 100 percent of what we want or we will threaten a default." Cruz suggests that the president's position is "give me 100 percent of what I want," which has validity. But the 100 percent of what he wants is what Cruz says is inevitable, an increase to the debt ceiling, in exchange for 0 percent of what Republicans want in exchange. Meanwhile, the House would like to ask for approval of the Keystone pipeline and changes to regulatory behavior and constraints on the EPA and a dozen other things. Granted, those demands haven't been presented yet — in part because the president is sticking to his "no negotiations" rule — but the ransom note is written, and Boehner has for weeks reportedly pushed his caucus to save their powder for a push for concessions during the much more economically dangerous debt ceiling fight.

Ultimately, the problem with this is that if this the thinking, no one's allowed to say it out loud. Inevitably it gets reframed as just "negotiation." In which case, see #1.