The right is usually more subtle (counterintuitively enough), moving the goalposts so that "centrism" and "moderation" have now come to mean "baby-killing, terrorist-sympathising, homosexual-agenda style sharia Kenyan anti-colonialism" or whatever, or by taking a consensus idea like "small businesses are important" or "apple pie is delicious" and saying the left is out to destroy that whatever it is because they hate everything good about America.
But I've rarely seen dedicated attacks on centrism from those aspiring to represent reasonable conservatism. Deconstructing Christopher Hitchens' blistering excoriation of Tea Party ideology, Ross Douhat says:
[D]o you know what else has often led to folly, disaster, violence and human misery? The “moderation” and “centrism” of the Western governing class.
He then lists these items as examples of "moderation and centrism in the Western governing class:"
1. The war in Afganistan.
2. The war in Iraq.
3. Medicare Part D.
4. Health Care Reform.
5. The Euro.
6. The Real Estate bubble.
7. The Bailouts.
8. The TSA & Current American Security State.
9. The Obama Tax Deal.
So, basically, everything currently viewed by a significant group of Americans as unpopular is not a product of American political extremes. I would consider this historical revisionism if it wasn't so baldly laughable.
Let's run down the list, shall we?
1. Al Queda operatives attacked us, and we went after them in Afganistan. As we should have done. The initial strategy, employed for nearly six years of war, was constructed by Donald Rumsfeld, an unabashed and now discredited neoconservative who hardly qualifies as anything approaching centrism or moderation.
2. The Iraq War. A dubious foray into faulty intelligence, preemptive war, misadventure and nation building, this was also the brain-child of neoconservatives like Donald Rumsfeld and VP Dick Cheney. Sold alternately as a vengeance response to the September 11th attacks, an search for WMD's, a strike against an imminent threat or just a chance to spread "freedom" around the globe, Democrats in Washington stupidly voted for this war because they were scared what the GOP would say about them in the media if they didn't.
3. Medicare Part D. An insufficient correction to badly administered programs, this is what happens when you attempt to address a problem without actually fixing said problem because doing so would leave you politically vulnerable to elements on the extremes demagouging the issue. Contrary to popular belief, centrism and moderation are not about punting on the hard choices, though they are often confused for that.
4. Health Care Reform. An insufficient correction to suicidally administered systems, this is what happens when you attempt to actually fix a problem with a centrist or moderate solution and then leave yourself politically vulnerable to elements on the extremes to proceed to demagouge the issue. While you expected more political support (that's why you were using a centrist framework, after all) the virulence of the opposition encouraged you to make significant changes to the already insufficient correction that keep it from actually fixing the problem.
5. The Euro is a very centrist idea. Europe wanted to simplify their economic relationships. The economy changed for the worse (because of economic extremists) and that simplification became a liability.
6. The Real Estate Bubble is what happens when economic extremists looking to maufacture Monopoly money legally inadvertently change the economy for the worse.
7. The Bailouts were required from keeping the American, and world, economy from collapsing due to the trillions of dollars in Monopoly money created by item 6. Another insufficient correction to a problem we shouldn't have had in the first place, the bailouts were a highly unpopular decision that had to be made. While saying "no" would have been chathartic, the risk of worldwide economic collapse was too great. I have no problem with this being labeled "centrist" or "moderate," but I have a problem with it being demagouged on the extremes, especially from the right, who had too big a hand in causing the problem the bailouts were intended to correct.
8. The TSA & Current American Security State. Really? This is only howlingly considered a centrist or moderate creation. For 8 years, this apparatus expanded under a right-wing Republican President, cheerled by right-wing punditry, and supported by media scaring the shit out of an already fearful America. For 8 years, we heard only that opposition to the expansion of this apparatus was akin to liberal support of terrorism and hatred for America.
9. The Obama Tax Deal is more bipartisan than centrist or moderate, but it comes close. While an acceptance of political realities put into place over the last 2 years (its main claim to centrism), it represents a "punt" on the difficult decisions that have to be made (bipartisan).
In total, however, that's 5 - 4 in favor of extremists owning these policies, with extremists directly scuttling the former centrist policies (the Euro, Health Care) and extremists directly creating the need for the latter centrist policy (the Bailouts and Obama Tax Deal). Extremists, on both sides and encouraged by their specific media, are causing too many of our problems.