Exceptionable exceptionalism
By 
One thing Liz Truss’s brief taste of lark’s tongue in aspic demonstrates, as Paul points out, is the superiority of the parliamentary model to the presidential model. The other thing is demonstrates is what an outlier the American brand of reactionary politics is:
On September 23, Truss looked on as Kwasi Kwarteng—her chancellor of the Exchequer, political soulmate, and personal friend—put forward a “mini budget” that would cut taxes on top earners, remove a cap on bankers’ bonuses, and cancel a planned corporate-tax hike. This was the “biggest package in generations,” he said. Dust off the Laffer curve, silence the “doomsters” worried about where the money would come from, and luxuriate in what even a sympathetic commentator described as a “Reaganite show of fiscal incontinence and Thatcherite derring-do.”
The left-wing opposition hated it—tax cuts for millionaires as Middle Britain struggled with high energy bills, rampant inflation, and rising mortgage costs—but so did the financial markets. Government bonds fell sharply, which left pension funds struggling to stay solvent. Five days later, the Bank of England was forced to step in and stabilize the British economy. A right-wing chancellor had implemented right-wing economic dogma, and the free market swooned—in horror.
The policy that got Truss sent away for brain salad surgery is just…the foundational Republican domestic agenda, from Reagan to Trump. “Cut taxes for the rich and corporations and hope it forces spending cuts eventually” is their most important priority, and often their only meaningful priority. I would love to know what British markets seem to actually care about the well-being of the country’s economy, while American markets seem only to care about maximizing the after-tax compensation of top-level executives.
Needless to say, these two issues are related. Republicans are willing to do the tax cuts themselves, but their plan for unpopular spending cuts involves holding a gun to the world economy to try to force Democrats to take joint (and, with a Democrat in the White House, primary) political responsibility for them. The ability to defuse responsibility is one of the things that encourages the kind of extremist reactionary politics, unpalatable to the country that brought you Maggie Thatcher, that dominates the Republican Party.