The influence of the Tea Party movement within and outside the USA is a real cause for concern.
Bob Altemeyer wrote The Authoritarians that discusses how traditional conservatism in America has been hijacked by the "Religious Right" and amoral authoritarian leaders. He also wrote Comment on the Tea Party Movement that builds on his earlier work. Both are worth reading and can be freely downloaded from his website.
A substantial source of funding for the organisations behind the Tea Party movement are the Koch brothers. Have a read of The New Yorker article The Billionaire Koch Brother's War Against Obama if you want an idea of the people that are really setting the agenda.
Unfortunately, we now seem to have some imitators in Australia. Annabel Crabbe wrote recently that Our culture warriors are fanning too much foreign fare and I guess the Australian Tea Party is an example.
The Tea Party probably wouldn't have gotten anywhere without Fox News. For an interesting article on the guy behind Fox News have a read of the Rolling Stone article How Roger Ailes Built the Fox News Fear Factory.
Edit 5/10: A Bloomberg article on Kock Industries Koch Brothers Flout Law With Secret Iran Sales.
Edit 16/2/2013: Study Confirms Tea Party Was Created by Big Tobacco and Billionaire Koch Brothers