...it is an iron truth of politics that prolonged success sows the seeds of future downfall. Revolutions run out of steam. They cannot be permanent. More damagingly still, what begins as an unorthodox and surprisingly successful approach calcifies into a stubborn orthodoxy that brooks no dissent, even as times and circumstances change.
The path to power is built upon compromise and flexibility: Thatcher always knew what she wanted to do, but she was also aware, in her early years, of how limited her room for manoevre was - not least because not everyone in her cabinet was on board. If progress was slower than she liked, it was also steadier than when, after 1987, she reigned supreme and hubris began to take its fatal grip. Similarly, Reagan was a vastly more adaptable President than current conservative folklore might have you believe.
In that sense, then. the troubles of Republicanism now and of the Tories in the last 15 years, were built upon their previous successes. The difficulty is that the second (or third) generation is rarely as talented or adaptable as the trailblazers who won power in the first place. Instead of finding fresh ideas and solutions, they inherit positions and prejudices that, because they worked once before, are assumed to be eternal truths rather than particular answers to particular problems at a particular time.