You know, there are some signs you can take from the phrases that people use that usually indicate when they aren't confident in their argument or feel like they are using. Two of them that I keep hearing from political shills, particularly McCain operatives recently when talking about Palin's foreign policy experience, are the phrase 'The fact is' and '[x amount of people] agree'.
When you keep repeating 'the fact is' all you are doing is trying to convince yourself. If it is a fact, it'll stand on its own. There isn't a need to identify it as such, particularly over and over.
The second phrase is more along the lines of trying to convince someone you are right by claiming lots of people agree with you so obviously it is right. Like 'millions of Americans believe the same things as Sarah Palin so her views can't be extremist.' Wow, color me convinced.
Anyway, just thought I'd throw those observations out there. And this isn't just in politics but in any conversation or debate really. Try it on your friends!