It goes on to suggest that the Tea Party are waning- however at the expense of the Republicans shifting to the right. (a classic response to a third party). Pay attention to the section on the ‘pendulum effect’ as it is an interesting analysis of how party ideological positions change.
Finally the article examines the troublesome nature of the new Republicans voted into the House in 2010. Suggesting that the need to constantly manage and cajole them into following the party line is wasting Boehner’s energy and limiting the efficacy of Congress.
More on the Republican shift to the right can be found in another Economist article titled ‘Are the Republican’s mad?’