More reasonable Republican politicians, they argue, would like to cooperate with Obama on bipartisan solutions but don't have the power to resist these extremists with the megaphones and so have buckled in lock step to their demands and become the party of "no" and the purveyors of gridlock.
The problem is that the presuppositions underlying those allegations are wrong. There may be some exceptions, but the large majority of leading conservative voices are doing their very best to save this nation from Obama's policies, which they believe are leading to the nation's financial, cultural and national security ruin. Obama is a leftist, very extreme by historical standards. To compromise with his positions would not be in the best interest of the nation but would advance the cause of leftism, so any pressure conservatives can bring to bear on Republican politicians to strongly oppose his agenda is laudable.
I can't conceive of too many situations in which splitting the difference with Obama has advanced or would advance the cause of conservatism or constitutional liberty. We wouldn't reduce our debt, for example, by agreeing to reduce the levels of increases in spending. We couldn't improve the quality, cost and availability of health care by agreeing to more government intervention when we believe in free market solutions. We couldn't prudently agree to a half-measure stimulus package when we believe stimulus spending not only doesn't stimulate the economy but does further increase the debt. We couldn't agree to some compromise reductions in our nuclear and conventional forces if we believe that even these lesser cuts would jeopardize our national security. We couldn't agree to meet Obama halfway on energy policy by signing on to policies that punish conventional energy only half as much and waste just half as many billions on quixotic green energy debacles.
We can get mired in a semantic argument over whether Obama is a card-carrying communist, a European socialist, an admirer of Hugo Chavez's and Daniel Ortega's or, as he says, a fierce advocate of the free market, but such quibbling is more misleading than the labels themselves.