US and UK politics have mirrored each other since post WWII

[Thunderbird is the word]

 While the UK was until arguably Cameron always slightly to the left domestically of the US it's funny that Labour and the Democrats or the Tories and Republicans have usually been in power at around the same time. Both moved to the right in the 80s with Clinton and Blair somewhat solidifying that in the 90s. Also the Prime Ministers and Presidents have mostly paralleled each other. Is there an explanation for why this is?

Clement Atlee=Harry Truman
Anthony Eden=Dwight Eisenhower
Harold Wilson=LBJ (moreso then JFK because of his working class background)
Edward Heath=Richard Nixon
James Callaghan=Jimmy Carter
Margaret Thatcher=Ronald Reagen (obviously)
John Major=George HW Bush
Tony Blair/Gordon Brown=Bill Clinton
David Cameron=George W Bush
Ed Millaband=Obama (assuming he wins)

[Thunderbird is the word]

It's Ed Miliband, and he's absolutely nothing like Obama.

Edit: And comparing Bush to Cameron is really not fair to Cameron at all. More rather, Blair is sort of like a combination of Clinton and Bush.

He kind of is in the sense that he'd likely be the second round of new labour in the same way that Obama ended up being the second DLC.