Welcome to the Taco Bell primary.

A few years ago, the storied purveyor of such authentic Mexican delicacies as Cheesy Beefy Melt and Nachos BellGrande launched an ad campaign based on three simple words: "Change is Good." At the time the slogan struck me as both sub-literate, like something from a self-help book for cavemen, and unreasonably optimistic--the changes in Michael Jackson's face, for example, have not been so good. But now four of the leading 2008 presidential contenders are making essentially the same argument to convince us to vote for them. What's good enough for chalupas, it seems, is good enough for Mitt Romney.

The Change Wars began on Sept. 5, when both Barack Obama and Hillary Clinton launched ads called, conveniently enough, "Change." Obama's was business as usual--as the new kid in town, he'd built his entire campaign around hope and the audacity thereof. But Clinton's was widely seen as strategic shift meant to neutralize Obama's appeal to "change" voters. Her new slogan: "Ready for Change, Ready to Lead." Obama, Clinton was arguing, may talk about change, but he isn't "ready" to make it happen. And in case you missed the point, Clinton has spent the three weeks since then repeating a single catchphrase -- "'Change' is just a word without the strength and experience to make it happen"--over and over again. And then over again.