Sen. John McCain delivered a nearly pluperfect supply-side tax-cut plan yesterday, one that is worthy of conservative support, and frankly a real eye-opener showing just how good he can be. I wrote about it in my latest column. But then he goes on NBC’s Today Show this morning and gets the whole energy story wrong. Oh my gosh. When asked about gas prices at the pump, and whether they could go any lower, Sen. McCain said he didn’t think so because “You’ve got a finite supply, basically, and a cartel controlling it.” This is exactly wrong. There is no finite...