In a rational world, Paul Ryan should have a fairly easy time in the upcoming debate against Vice President Joe Biden. Ryan is a man who has mastered the intricacies of legislation and the federal budget while Biden has shown scant interest in anything in his senatorial career other than the AMTRAK schedule from Washington, DC to Delaware.

Unfortunately, we don’t live in a rational world. We live in one where Barack Obama is president AND Joe Biden is vice president. To win a debate against Joe Biden one must be prepared to engage with a man who has hardly more than a nodding acquaintance with the truth.

Most of us are familiar with Biden’s ill-starred run for the Demcocrat nomination in 1988 as part of the Seven Dwarfs. He was forced out when it was revealed that he’d not only plagiarized a speech by British Labor Party leader Neal Kinnock, he’s actually gone so far as to steal Kinnock’s biography, claiming to be the son of an impoverished coal miner. (Though to his credit, when Gary Hart was dropped out due to his marital infidelities Biden remarked, “We’ve lost Horny.”) To this day, Biden claims he was “raised in Scranton (PA)” though he left when he was 10 years old.

This should be a danger sign.

The fact is that when Biden gets put in a tough position he will simply make stuff up. For instance, Jonah Goldberg relates this tale:

The most notorious comes from Biden’s 1988 bid for the Democratic presidential nomination. He had been hounded about his law-school record and plagiarism problems (among other things, he copied five pages from a law journal for a 15-page paper and then claimed it was a footnoting error), and he was asked a question about his academic record by a resident of New Hampshire.

He responded: “I think I have a much higher IQ than you do, I suspect.” He went on:

I went to law school on a full academic scholarship, the only one in my class to have a full academic scholarship. In the first year in the law, I decided I didn’t want to be in law school and ended up in the bottom two-thirds of my class and then decided I wanted to stay, went back to law school, and, in fact, ended up in the top half of my class. I won the international moot-court competition. I was the outstanding student in the political-science department at the end of my year. I graduated with three degrees from undergraduate school and 165 credits — only needed 123 credits. And I would be delighted to sit down and compare my IQ to yours.

Most of these statements were outright lies.

Fast forward to 2008 and his debate with Sarah Palin:

When we kicked — along with France, we kicked Hezbollah out of Lebanon, I said and Barack said, “Move NATO forces in there. Fill the vacuum, because if you don’t know — if you don’t, Hezbollah will control it.”

Now what’s happened? Hezbollah is a legitimate part of the government in the country immediately to the north of Israel.

Perhaps this happened in an alternate universe, but Hezbollah has never been kicked out of Lebanon.

And therein lies the danger for Paul Ryan. When you are debating someone you expect a modicum of honesty. Biden is as close to a psychopathic liar as we’ve had as either president or vice president. Where Bill Clinton would lie just to keep in practice, Joe Biden is a personality who lies without reason and seems to have the ability to actually believe his own lies.

Ryan will be in a format where he cannot fact check Biden and as a result he will probably have to let Biden get away with telling some otherworldly lies simply because he will not be able to disprove them on the spot.