The Libertarians (IMO) shot themselves in the foot by opposing the War in Iraq. Many of them sounded just like anti-Bush Democrats in their rhetoric on the war, and I think most libertarian/conservatives who are willing to give Libertarian candidates a look didn't care for what they saw last year. I'd have gladly voted for Georgia's Libertarian Senate candidate over Johnny Isakson last year if he hadn't sounded like Teddy Kennedy when it came to Iraq.
You could make a case that Iraq was not the immediate threat though. Yes, the world is better off without him but one could make the case that bringing down the House Of Saud or going after Pakistan for their harboring of Bin Laden and crew might have made a bigger impact on terrorism. And, Iran and Korea were probably more of a threat to us than Iraq.
Seems on the whole that there are a lot of people out there who don't like us....
screw em