As Ronald Reagan demonstrated, it is still possible to progress if not from a log cabin at least from obscurity to the White House. It is also rare.
Although Britain has, since 1653, had nothing approaching a single, codified constitution, it did for a very long time possess a broad cult of constitutional writing. The Petition of Right of 1628, like the Bill of Rights of 1689, was a cherished text. So, most of all, was Magna Carta.
Even leaving aside its military bases, America's influence on the domestic ordering of British life has been enormous, though sometimes unrecognised.
Any kind of new U.K. federal system would almost certainly demand the creation of a written constitution. Properly drafted, such a document could, among many things, pin down more effectively the proper dimensions of prime ministerial power.
Although England, and the rest of the United Kingdom, possesses momentous constitutional texts and significant statutes, since the 1600s there has been no systematic attempt to codify the powers and limits of the British executive and the rights of those it governs.
Monarchs, aristocrats, and other powerful and wealthy individuals have usually been happy to have themselves and their possessions and families immortalised in oil paintings and sculpture. But before the 20th century, such dynasts rarely commissioned artworks that set out to represent society as a whole.
I write to relieve an intellectual itch. I stumble across a hitherto neglected set of events, transformations, characters, or source materials from the past, and they nag at me until I make sense of them in words. But I also write to seduce and to make my readers think.
Many Americans remain very interested in royal goings-on in general, and not just because of their soap-opera appeal. To a greater degree than any other polity, Britain functions as Americans' defining 'other.'
If the U.S. and its allies can invade a weaker country on the excuse it is abetting terrorism, then why should not India, say, launch a pre-emptive strike against Pakistan on the self-same grounds?
I was in Boston, Massachusetts, when Princess Diana died.
Even at its most powerful, Britain always needed alliances with other European states. There would almost certainly have been no British victory at Waterloo, for instance, without the assistance of Prussia.
America's entire homeland security enterprise positively invites questions even as it strives to reassure.
It was hardly their own shining abilities alone that allowed a son, two grandsons, and a son-in-law of Winston Churchill to make their way into parliament.
America's soldiery, like its war dead, comes disproportionately from its southern states and from its aspiring poor - both white and black.
Had Barack Obama been obliged to take his degree at the University of Akron, say, it is doubtful that his progress would have been remotely as stellar.
The argument that any income redistribution is tantamount to socialism, and that socialism has always been unAmerican, has helped legitimise keeping taxes on America's very wealthy very low.
In Britain, British history is naturally a mainstream subject. Step outside your own narrow specialism, and you can find yourself treading on someone else's toes. But in America, British history is an eccentric, minority pursuit, and while this can be intellectually isolating, it also permits extraordinary freedom.
In the twentieth and twenty-first centuries, products and tastes developed in America have increasingly influenced lifestyles in Europe, whereas in previous centuries, it was generally the other way around.
For a very long time, loyalists were often left out of patriotic American histories of the revolution. Or they were caricatured as upper-class Tory reactionaries, or - rather like the Jacobites - made the subject only of nostalgic antiquarianism.