You're ignoring the huge infighting in the GOP, for what reason, exactly?
Because at the end of the day, they vote together in 99% of the elections (excepting the few where both sides field a candidate). They are internally divided, but 100% unified when the question is, "will you vote for Nancy Pelosi, or her opponent, who is a marmoset dressed in drag". They'll vote against the Democrats every time, no matter what.
In the question of far-right Republicans and off-the-charts-right Republicans, it doesn't matter. Alien Vs Predator's tag line comes to mind. Whoever wins, we lose.
Reading the examples in your link, they look to be Teabaggers vs Republicans. The Teabaggers are more conservative than the Republicans. So the fighting doesn't matter. Where are the liberal Republicans? The small government Republicans don't have a voice in the fight.
Or are you one of the ones that thinks the Teabaggers are small-government Republicans? I've been to meetings, they are pro-religion Republicans looking to impose religious worship on us all. The reason the country is failing is that women can have abortions, whites can marry blacks, and taxes can buy something other than guns. Higher taxes for more guns is a good thing, to the Teabaggers I've met. They don't want a smaller government. They just want everyone on welfare to be dead (and by everyone, I think they really mean the blacks, as there are more whites on welfare than blacks, but that never is brought up).
I've been a member of the Libertarian Party, and the Republican Party and attended Teabagger meetings (back when they actually called themselves teabaggers, and so long as they claim they never did, I'll never stop using it), but on Slashdot I'm continually told that I don't "understand" them. Often by people who have never been to the actual meetings where people stand up and say stupid racist stuff, to a cheer of people.
Oh, and I've never been a member of the Democratic Party. And didn't vote for Clinton or Obama (though I never voted for a Bush either).