Earlier this year, in a nationally televised debate, Tim Russert confronted John McCain with some of his inconvenient admissions about the economy: "You have said repeatedly, 'I know a lot less about economics than I do about military and foreign policy issues.'" McCain was incredulous and dismissive, "Actually, I don't know where you got that quote from."

Soon after, McCain appeared on "Meet the Press," and Russert returned to the subject and responded to McCain's slight ("I got [the quote] from John McCain"), highlighting McCain's record of admissions about economic ignorance. "OK," McCain said, no longer able to deny reality, "Let me tell you what I was trying to say and what I meant."

Wednesday morning, in a disconcerting example of dishonesty, McCain went back to pretending his quote collection doesn't exist.

I know it's best to be cautious about throwing around words like "lie," but McCain has been confronted with his own remarks on multiple occasions. He knows what he has admitted, and has been asked to explain his comments. What Robin Roberts said was obviously and demonstrably true -- McCain has admitted that he's "not exactly an expert when it comes to the economy."

Why would McCain appear on national television and say something he knows to be false? Given his emphasis, especially lately, on honesty in the campaign, why take the risk by lying like this?

Not only does it bring McCain's character into question when he makes obviously false claims, but it merely serves as another opportunity to remind folks about McCain's own admissions:

* Seeking to explain his shift to the left on economic issues, McCain claimed: "I didn't pay nearly the attention to those issues in the past. I was probably a 'supply-sider' based on the fact that I really didn't jump into the issue." (January 2000)

* "I'm going to be honest: I know a lot less about economics than I do about military and foreign policy issues. I still need to be educated." (November 2005)

* "The issue of economics is not something I've understood as well as I should," but "I've got Greenspan's book." (December 2007)

Even one of his top campaign advisors has admitted that McCain has made these comments. Why deny what is plainly true?

What's more, in addition to the lie about his rhetorical record, it's worth noting that McCain's admissions happen to be accurate. He has demonstrated over and over again that when it comes to economics, McCain is painfully confused.

I realize this must be embarrassing for McCain. He admitted to not understanding economics, and then went about proving how right he is. But that's no reason for McCain to go on "Good Morning America" and lie about what he has said.

It's all right for a candidate to spin his or her record, but bogus denials are likely to cause a campaign trouble.