Follow the link for a list of reversals made by both politicians.
The contenders in this year's US presidential election are no exceptions - both John McCain and Barack Obama have engaged in some nifty repositioning.
Mr McCain's U-turns have mostly increased his appeal to the Republican Party's base, placing him on a rightward trajectory.
Barack Obama has been performing a more traditional manoeuvre: running to the left during the primaries, when party activists need to be wooed, then shifting to the centre once the nomination is clinched.
Flip-flopping politicians will always attract charges of hypocrisy and opportunism: it may be worth it if it helps them win over undecided voters in the middle, but when the goal is to shore up their political base, the benefits are much less clear.
Further evidence to support the median voter theorem?