I'm not saying this to be mean. It's because I think the country is best served by having 2 major parties with differences but close enough together that co-governance is workable.
The Republican party has been moving steadily to the right for a couple of decades. Over those years, they have managed to bring most of their constituency along with them. But groups have been falling (or jumping) off the wagon for years. The party has survived by improving the turnout of its base in recent elections. That can't continue; there are limits to the "turnout strategy". If ythey were to (impossibly) achieve 100% turnout in a shrinking base, where can they go in the future.
Extremism is a strength and a weakness. Yes, it improves the percentage of the turnout, but it increases the opposition turnout as well. There were some startling examples of the extremity in the Republican party this year. Looking back on the primary elections, it is clear that almost all of the candidates were actually to the left of the base. This drove all of them to make ever more extremist statements. Whoever the eventual nominee was to be, he was going to be dragging extremist views (and perhaps more importantly, soundbites) into the general election campaign.
The extremism also affects campaign planning. I saw an interview with some Republican strategist (forgive me I lost track of the name) who was genuinely shocked by the election results. He had watched all the Fox News channel discussions, he had followed the Rasmussen polls carefully. And they were WRONG! Shocked, he said, SHOCKED...
I hope I am not saying anything controversial here, but Fox News was created to be a media outlet for (and controlled by) conservative Republican views, unfiltered by standard mainstream news channels. The idea was originally proposed by top Republican strategist Roger Ailes to fellow Republican leaders in the 1990s. Guess who is the president of Fox News? Roger Ailes.
Equally, Rasmussen appears to be a polling company created to present positive Republican spin on voter preferences for the political benefits of influencing voters who can be swayed be wanting to support a "winner". They are politically (as opposed to professionally) convinced that Republican voters are under-represented in the mainstream neutral national polls. So they deliberately over-weigh their own Republican poll numbers to "correct" the perceived inequity.
So when Rasmussen gets ties, they increase the Republican support a few percentage points. If behind, they make it tied. If ahead, they make the Republican candidates more ahead. Their professional Republican customers know this, but then they believe it! So when Rasmussen said Romney/Ryan was ahead by 5% in most of the "swing states" where they were actually slightly behind, and had an even chance in other states where they were actually well behind, the Republican leadership and candidates acted on the Rasmussen polls and ignored ALL THE OTHER (more professional) polls.
The results were a substantial Presidential electoral defeat and shocking (to them) Senate and House defeats.
Next time: Why this is all happening...
[Disclaimer: I have an undergraduate degree in "Government and Politics" (with a minor in History - American Politics), but mostly, I have maintained a possibly unhealthy interest in the practices and strategies of modern political campaigns. My favorite book is 'They Also Ran' the story of the men who were defeated for the Presidency, Irving Stone]