I thought the Republicans' "flip-flop" accusations against John Kerry were ridiculous the very first time I heard them. There is no law against changing one's mind. It is natural to revise an opinion when new information is available or circumstances change. Besides, many of Kerry's alleged flip-flops were really just a matter of supporting/opposing similar bills because of differences in their details, such as funding. This is a common practice in Congress among both parties.
The main reason the accusations bother me is that I know Bush has "flip-flopped" on many issues, too. One obvious example is that he said gay marriage was an issue for the states, then he decided to push for a constitutional amendment. Thanks to Eric Zorn, I now have a list of thirty Bush flip-flops from the American Progress Action Fund. Anyone who thinks Kerry is the only politician to change his mind ought to read this: President Bush: Flip-Flopper-In-Chief.