Adam Clancy is a freelance writer in Washington, DC and a contributor to the Via Meadia blog:

I sadly cannot share Nick Bryant's hope that John Roberts' Supreme Court ruling on the Affordable Care Act heralds a new age of civility and reasonableness in American politics.

In fact, nothing demonstrates more clearly the lack of reason in the contemporary American political debate than the furor over healthcare. As Ezra Klein meticulously detailed in a recent New Yorker essay, the idea of the individual mandate (the core plank undergirding the entire law and the subject of Republican ire) was first proposed in 1989 by the Heritage Foundation, one of the most conservative think tanks in Washington. For the next twenty years, Republican politicians repeatedly argued in favour of the mandate as an alternative to Democratic dreams of introducing a single payer system modeled on places like Australia and Canada.

It also happens to be the same plan passed by Mitt Romney in Massachusetts; a plan that has delivered near-universal health insurance to the people of that state, and a plan that Romney has since retreated from. In the 2012 Republican Party, as the ferocity of the conservative backlash to the Supreme Court's decision so vividly demonstrates, support for an idea incubated by the Heritage Foundation is now considered heresy.

If a new era is indeed upon us, I would also ask why the Republican-controlled House will this week hold yet another purely cosmetic vote to repeal the law? (This will be the 31st such vote the House has held since January 2011.)

Bryant also points to Mitt Romney's victory in the Republican primary as evidence that the Tea Party crowd does not exert a stranglehold on the GOP. Although it is hard to pin down Romney's core beliefs, I agree with Bryant to some extent – it does seem unlikely that Romney is an ideological warrior in the mould of, say, Rick Santorum.

Nevertheless, the pragmatic wing of the Republican Party, if indeed it still exists, is winnowing by the month. The latest 'moderate' victim was Senator Richard Lugar, who in May lost his primary fight to a Tea Party-backed firebrand. Among his conventional conservative positions, Lugar supported a balanced budget amendment, voted against the 2009 stimulus as well as Obamacare, and took the lead in fighting President Obama's decision earlier this year to halt construction of the Keystone Pipeline. But apparently Senator Lugar is not conservative enough for the current Republican Party. He joins other conservative stalwarts, such as Bob Bennett of Utah, in being rejected by the Tea Party and getting booted from the Republican Party as a result.

In a survey of current congressional voting patterns, National Journal found that the most liberal Republican in the Senate was further to the right than the most conservative Democrat. The Mudbloods are gone and the result of this ideological purity is that, should Romney get elected, he will have to negotiate with what political scientists have called the most conservative Republican Party in over 100 years.

In their new book, the authors Thomas Mann and Norman Ornstein describe the institutional paralysis induced by the Republican Party's unyielding obstructionism:

"However awkward it may be for the traditional press and nonpartisan analysts to acknowledge, one of the two major parties, the Republican Party, has become an insurgent outlier—ideologically extreme; contemptuous of the inherited social and economic policy regime; scornful of compromise; unpersuaded by conventional understanding of facts, evidence, and science; and dismissive of the legitimacy of its political opposition. When one party moves this far from the center of American politics, it is extremely difficult to enact policies responsive to the country’s most pressing challenges."

What's remarkable is not so much the substance of Mann and Ornstein's jeremiad – indeed it is a standard liberal critique – but that it is coming from these two men. Mann, from the liberal Brookings Institution, and Ornstein, from the conservative American Enterprise Institute, are about the least likely bomb throwers around. They are deeply respected on both sides of the aisle. Clearly, as the subtitle of their book affirms, 'it's even worse than it looks.'

Nor are Mann and Ornstein alone. A steady stream of former Republican insiders has been articulating similar criticisms. Here, for example, is Mike Lofgren, a Republican Congressional staffer who retired last year after 28 years on Capitol Hill:

"A couple of years ago, a Republican committee staff director told me candidly (and proudly) what the method was to all this obstruction and disruption. Should Republicans succeed in obstructing the Senate from doing its job, it would further lower Congress' generic favorability rating among the American people. By sabotaging the reputation of an institution of government, the party that is programmatically against government would come out the relative winner."

One final point: I share Bryant's belief that this dysfunctional politics is limiting the ability of the US to restore its economic vitality (although I reject the notion that America is a country in decline). But I'm not holding my breath that any substantial change will occur soon. Even though a series of dramatic fiscal and budgetary decisions looms just after the election, the state of play right now points to a continuation of the status quo: a narrow Obama re-election, Democrats hanging on to control of the Senate, and Republicans doing likewise in the House. Until and unless the Republican Party adjusts its political calculation and begins to brook at least some compromise, expect more of the same.