One thing to watch out for are people who insist that the basic principle of what they're saying is right, even if the specific situation they're describing doesn't support their case. For example, when Michael Ledeen and Rush Limbaugh got caught attacking Obama for a thesis he didn't write, they blamed Obama, saying that "It worked because it's plausible" and "I know Obama thinks it." Sure, their specific attack was wrong, but that's ok, because they were right anyway, and that's all that counts.
Similarly, war-hawks made this error when they decided that WMD's in Iraq would justify their war, even if we didn't have any real proof that they existed. When forced to support their claims, they cherrypicked dubious intel which they themselves had strong-armed into creation, and felt sure that reality would eventually support their claims. And once the piles of WMD's were found, their invasion would be justified, even if their real reason for wanting to invade had nothing to do with WMD's. Needless to say, the lack of evidence proved correct, while their beliefs proved to be false; not that this hurt their career paths in the least.
But it's not that reality has to support your position every time a situation arises, just as long as it occurs enough to establish a reliable pattern. So conservative claims that ACORN is corrupt merely because they found a few low-level employees who were bad are invalid, unless they can establish that this corrupt behavior is the norm. Conversely, liberals don't need to prove that every ACORN employee is pure in order to defend the organization.
And the overall flaw here is that you might find yourself in a position in which no facts actually support your case. Or if there are some, they're outliers, rather than examples which support a pattern. And you'll find yourself in the lousy position of trying to find facts to support your beliefs, rather than basing your beliefs upon those facts. And that's called cherry-picking.
It's not enough to be able to find some examples to support your case. You have to be able to show that almost all the examples support your case. So if you suggest that Obama is spying on peace groups, it's not enough to find one guy who started spying before Obama took office; particularly not if there's no proof the guy was actually working for Obama. Rather, you need to show many such people, throughout the country. And their existence means nothing unless you can actually link this back to Obama in some way.
Yet this is an error seen far too often. People want to find things that justify their beliefs. And if they're convinced that something is true, then finding any sort of confirmation is a very tempting treat. After all, if Obama started spying on peace groups, you might not find many such examples. But that doesn't permit you to take the few examples you have and use them as absolute proof. No, you're just stuck hoping that another example turns up.
And it's not your opponent's job to prove your examples wrong. It's your job to make sure you're not making this mistake. And the more you want to find something to be true, the more you need to double-check to make sure that it's true. Self-delusion is a horrible affliction which is almost never caught.
So if you have no proof whatsoever that Obama has ever actually expressed disdain for our Constitution or the aristocracy that established it, you really should do a tad bit of research first before denouncing him for saying these things. But when people have a point to make, facts are little more than props used to support their case. God forbid we actually try to learn anything from them.
Oh, and curioiusly, this Yahoo Buzz Log post actually describes Michael Ledeen as an "unknown blogger", while his Wikipedia page seems to know quite a bit about him and would seem to suggest that he's more than a mere blogger. I'm not sure if this is an example of Yahoo Buzz trying to ridicule bloggers or if this simply shows that they don't know much about political people, but either way, it's a trend to keep an eye on. Apparently, anyone who blogs these days automatically becomes an unknown.