This is a speculation based on observing the way that British and American politics seem to have been running on parallel lines since the end of World War 2, switching from left to right and back again within a few years of each other.

The timing of the changes is partly governed by the fact that the U.S. operates on a fixed-term electoral cycle and the U.K. doesn’t. This flexibility means that a change in the political mood can sometimes be expressed first on the British side of the Atlantic (though it also means that an “old regime” might hang on for a while longer).

The pattern goes like this;
When Japan surrendered in 1945, both countries were under comparatively left-wing governments- a Democrat administration and a Labour government- which lasted beyond the end of the decade.

The Fifties were dominated by conservatism. There was the Eisenhower era (from 1952), and in Britain there was a time of Conservative government (from 1951), epitomised by Harold Macmillan’s observation that “Some of our people have never had it so good.”

The Sixties were ready for something a little more radical- the Democrats under Kennedy-Johnson (from 1960) and the Labour party under Harold Wilson (from 1964).

Nevertheless, at the end of the decade, they both gave way to more conservative individuals- Richard Nixon (from 1968) and Ted Heath (from 1970). (I swept to power myself in 1970 as the winning candidate in our school’s Mock Election).

Nixon and Heath were both forced out a few years later, but the change happened more quickly in Britain. Ted Heath was able to call an unnecessary election in early 1974 and get himself thrown out almost instantly. Whereas, even after Nixon resigned, the American Constitution kept the Republicans in power until 1976.

So, in the second half of the Seventies, there was, once more, a Democrat administration and a Labour government. Neither of them impressed people by the way they handled crises, and there was another conservative reaction in both countries. Once again, the change happened in Britain first. Maggie Thatcher was able to force an election in 1979 by winning a “No Confidence” vote in the Commons, while Ronald Reagan had to wait for the fixed election date in 1980.

The Reagan-Bush and Thatcher-Major years were a time of renewed conservative domination. The compatibility between Reagan and Thatcher was noted at the time. Leftists will fondly remember the famous film poster parody, with Reagan carrying Maggie in his arms;
“She promised to follow him to the end of the world.
He promised to arrange it”.

Finally, at the end of the century, conservatism gave way to Clinton and Blair. This time the American change happened first, partly because John Major won an election which nobody was expecting him to win.

Taken individually, all these changes can be explained by local factors, like the Vietnam issue on one side of the Atlantic, and strikes in the nationalised industries on the other. Nonetheless, when the pattern is taken as a whole, there’s a remarkable sequence of parallels.

I don’t know that the mechanism behind it need be anything more mysterious than having a similar culture with similar reactions to world affairs and economic issues. This would include being more resistant to Socialism than the European countries. Certainly British politics and European politics have not been running in parallel to anything like the same extent.

At first glance, the new century seems to have disrupted the pattern. The British equivalent of Clinton remained in power while America was moving from Left to Right and back again. Or did Tony Blair end up as the British equivalent of Bush Junior after all? Anyway, with the arrival of Gordon Brown and Obama, the two countries were apparently back on parallel tracks.

This brings us to the significance of the 2010 election in Britain. As everyone knows, Gordon Brown found himself discarded, and replaced by David Cameron and the Coalition. So the question is whether this shift in the political mood presages a similar shift on the American side of the Atlantic.

Does it imply that Obama might find himself replaced by a Republican President, on the basis of a rather slender majority?

Or does the precedent suggest, perhaps, that the mood-shift towards conservatism will not be strong enough to bring the Republican party to power unless they can reach an accommodation with more moderate forces?

Parallels are not so easily found before World War 2, partly because the straight left/right divide is not fully valid in the U.S. For example, at the beginning of World War 1, the U.S. has a Democrat President and the U.K. has a Liberal Prime Minister. Then, after the war, both countries fall back on conservatism, "return to normalcy", with a series of Republican Presidents and the 1922 Conservative revolt against Lloyd George. In Britain, though, this Conservative domination lasted until the end of the next war, whereas in America it was Franklin Roosevelt who became dominant..

One of the reasons for this must be the difference in party structure. In Britain, the untried Labour Party pushed aside the Liberals as the champions of reform, and were never able to obtain a majority. Whereas FDR could still benefit from the Democrat loyalties of conservatives in the South. (Did Governor Wallace and Ronald Reagan between them kill off this tradition?)

Today, the UK has a "national government" in all but name.

By that term, I draw an analogy to the grand 1930's political coalition of Conservatives, Labour & Liberals which governed the UK during and after the Great Depression. Because, with the Shadow Chancellor's announcement about public spending yesterday, all three major British political parties now sing from the same hymn sheet.

Yet there's no such coalition in the US Congress, there's just a steady drift to the right & the Republicans.

So, no, I can't see any immediate parallels at this moment, apart from very general cluelessness on the part of everyone in charge ... they just don't know how to fix our financial predicament,

I understand what you mean, but on many occasions the party holding the US presidency is different to that holding one or both houses of the US Congress, whereas in the British system the Prime Minister always represents the majority in the lower house of Parliament.

You say Clinton and Blair walked the walk, but in many ways Clinton's presidency was defined by the Republicans taking the House of Representatives in 1994 ... the USA went right but the UK was heading left. They were out of step ?