Stuck at a parking meter yesterday with only a $20, I darted into a convenience store and asked for change. Vast media hordes instantly descended, clamoring for interviews.

Change. You hear the word over and over, every four years, presidential candidates digging it out of their pockets and throwing it in every direction, hoping to hit voters. (A Democrat was actually killed in New York City in 1988 when he was struck by change thrown from the Empire State Building by Michael Dukakis.) The need for change has never changed in our elections -- it's the main reason we have them. Yet every four years the media treat it like a phenomenon akin to the introduction of the secret ballot. And we eat it up, because if there's one thing we refuse to change it's our insistence on change.

Now, with the nation's second Caucasian primary underway, change is once again in the air. Because things are all screwed up, and we have to unscrew them. With change. (In this sense, our government is like a light bulb, but in reverse: you have to change it to unscrew it.) And what we're looking for is an "agent of change" -- someone who, ideally, can work "change" into the first five lines of a stump speech at least four times.

Change is so important that yesterday Mitt Romney said he stands for change because he's the Republican most like Barack Obama, except for being white and wealthy. But Obama is riding high right now, so he's the change candidate who's satisfied with the status quo.

Hillary saw the change tsunami coming months ago, and immediately jammed the word into a new campaign slogan: "Ready for change, ready to lead." Unfortunately, her plunge from frontrunner inevitability is change she wasn't ready for, although you have to admire the resilience reflected in her new new campaign slogan: "Already changing, because the lead changed."

John McCain, meanwhile, announces proudly that his positions never change -- which is quite a refreshing change. John Edwards promises to change everything but the part in his hair. Rudy Giuliani is stuck explaining why he keeps changing wives. Fred Thompson is trying to change into someone who seems to give a shit. And the supporters of Mike Huckabee look forward to changing a constitutional democracy into a Christian theocracy.

Then there's Dennis Kucinich and Ron Paul. They're the candidates who stand for serious, bold, honest-to-God change, not just empty sloganeering. So, naturally, they're not even allowed to participate in debates.

What a great system we have! I wouldn't change a thing!

But I'll leave the last word to David Bowie, who knows a thing or two about change:

Ch-ch-changes
Where's your shame
You've left us up to our necks in it ...