If you're one of those people who has already dismissed the idea of Bob Barr's Libertarian Party candidacy being a serious threat to the GOP, check out Martha Zoller's thought-provoking piece at Pajamas Media. Barr seems to have learned a thing or two from the previous joke candidates:

One of the big stumbling blocks for old-time Libertarians was their view on open borders. In light of the existence of the nanny state in America today as well as a less than free market impeded by regulation, Barr is taking a more forward view than the Libertarian Party now professes on illegal immigration. He believes there must be border security but doesn't support a fence. In addition, he believes it is an issue of sovereignty. Libertarians have acknowledged that in a perfect world involving a free market and personal responsibility, an open border is not a threat because you have to make your own way. But this is not a perfect world and Barr's position on border security may play well with many voters.

There are many reasons why people decide to run as alternative party candidates. Sometimes it's to sell a book, get notoriety, or work to further an issue. Few candidates run with the idea they can win the presidency. However, if there is any election in recent years where an alternative candidate can make a difference, it is this one. The Republicans have their candidate. The Democrats are still tearing themselves apart. But there is still money out there for a candidate tap. Many people thought Ron Paul was a fringe candidate, but you can't deny his following and ability to raise money. This year a strong third party candidate could really muck things up.

In any case, I still think Barack Obama will do more to unite the Republican Party than Bob Barr will to divide it.