I think Nate Silver is brilliant and very, very good at predicting elections, but he’s only as good as the data he has to work with, and he is capable of making small mistakes or developing models that are too clunky to capture some of the finer grains in campaigns. One example is his reliance on a “fundamentals” score that really serves as a stand-in for good data in the early stages before he has a robust sample of polls to work with.

If you look at the fundamentals of a state like Kansas, it’s going to look like the Republicans have a huge advantage over the Democrats. The state hasn’t elected a Democratic senator since the 1930’s and it vastly prefers Republican presidential candidates. The voters are very conservative and the president is quite unpopular there.

But this all masks a rather serious split within the Republican Party in Kansas. Under the leadership of ultra-conservative Governor Sam Brownback, moderate Republican lawmakers were purged from the legislature and replaced with wingnuts. Dave Weigel termed it The Great Kansas Republican Purge of 2012. And, yes, Koch Brothers money made it possible.

Much of the dispute focused on moderate Republican opposition to Governor Brownback’s proposed income tax cuts, which were seen as fiscally suicidal. And that has turned out to be the case, with both Moody’s and Standard and Poor’s recently downgrading the state’s credit rating.

The most prominent of those purged Republican lawmakers is former state Senate president Steve Morris:

Brownback’s critics say the degree of the tax cuts is threatening basic services, not to mention the state’s bond rating and requirement to balance the budget.

“People are concerned about education,” said Steve Morris, a member of Republicans for Kansas Values, a group of more than 100 GOP members who are backing [Democratic candidate Paul] Davis. “They’re concerned about transportation.”

Morris is a former Kansas state Senate president who lost a 2012 Republican primary to a Brownback-favored Republican. He said he is backing Davis not because of “sour apples,” but “concern about the direction the state’s heading in.”

The result is that Brownback trailed Davis on all three polls taken in August. Rasmussen had Brownback down by 10 points. Needless to say, when the incumbent governor is doing this badly, the “fundamentals” of the state don’t count for much. Brownback will be on the top of the ticket, not President Obama. And that’s a problem for Sen. Pat Roberts. With a very large contingent of angry moderate Republicans headed to the polls to defeat Brownback, might they also cross-over to beat Roberts?

That possibility is what led me to write about this race last week, and I noted that a Public Policy Polling survey had found Roberts narrowly beating Democrat Chad Taylor in a two-way race but losing to independent Greg Orman in a two-way race. Might Chad Taylor be enticed somehow to drop out of the race? Would Greg Orman agree to caucus with the Democrats?

Well, today, Chad Taylor dropped out of the race, leaving Orman a one-on-one contest with Sen. Roberts. We can only speculate about whatever behind the scene machinations went on to make this happen because Chad Taylor is keeping mum.

Taylor, reached by phone in his car, tells Kansas First News that he turned in the papers to withdraw at 4:15 p.m. Wednesday.

When asked why, Taylor declined to comment and says he “would do some press later in the week.”

As I pointed out last week, Prof. Sam Wang saw this possibility as a complete game changer:

If the [independent senators] and the Democrats win exactly forty-nine seats, Orman would have it in his power to provide—or deny—the critical fiftieth vote to control the chamber. In all the outcomes simulated in my model, this event has an almost thirty per cent probability of happening. Added to the Democrats’ chances of gaining control without Orman, the total probability of combined Democratic and independent control would be eighty-five per cent—a total game-changer.

Nate Silver still gives Roberts a 56% chance of winning against Orman, but that is because his “fundamentals” number gives the Republicans a 25% advantage. That’s an advantage that takes no account of the civil war that has gone on inside the Kansas GOP over the last two years. It takes no account of this, which happened yesterday:

More than 70 former Republican lawmakers announced their support for the independent candidate for U.S. Senate over incumbent Republican U.S. Sen. Pat Roberts on Wednesday.

Traditional Republicans for Common Sense, which is made up of moderate Republicans who have served in the Kansas Legislature, chose to endorse Greg Orman over Roberts and Democrat Chad Taylor.

“Our members know leadership because they’ve been leadership,” said Jim Yonally, the group’s chairman and a former state representative from Overland Park. “Our members have been there. They’ve been on the frontline. They’ve had to make the tough decisions.”

The group sees Orman as a pragmatist who can broker compromises between the two parties, said Rochelle Chronister, who has previously represented Neodesha in the House and served as chair of the Kansas Republican Party.

“This has been the most do-nothing Congress ever,” Chronister said. “They can’t even pass an appropriations bill to keep the government running.”

Like I said, I think Nate Silver is brilliant. But Harry Reid ain’t no dummy either. And I think Reid just cooked Pat Roberts’s goose.