From the liberal perspective, the more shameless the lies, the better because the target of the scandalous accusation and his defenders will often waste inordinate amounts of time and energy fighting ridiculous, unfounded allegations that a certain percentage of uninformed Americans will simply assume are true without evidence.
2) The Anonymous Smear: Want to launch an attack at a conservative, but don't have a credible source handy? No problem. Just take a vicious critic or an unreliable source and make them "anonymous."
CBS did it with Bill Burkett, who provided them with the fake "Bush was AWOL" documents during the 2004 campaign. Had they revealed who he was, the story would have been treated as not credible from day one.
If even that proves too troublesome, some members of the media (I strongly suspect Seymour Hersh is guilty of this) just make things up and attribute them to non-existent sources. Since their sources are anonymous, unless they make the mistake of including verifiable details like the New Republic's Scott Beauchamp, it's almost impossible to prove they're lying.
3) The Teary Eyed Spokesman: One of the Left's favorite tactics of late is to pick pathetic figures we're supposed to feel sorry for as spokesmen. That way, if you try to respond to the lies of someone like Cindy Sheehan, you're accused of picking on the mother of a dead soldier. If you try to respond to the lies of Max Cleland, you're accused of picking on a crippled vet. At this point, I'm surprised they haven't found a gaunt, stuttering orphan to serve as Obama's Press Secretary. Worst-case scenario, he couldn't do much worse than Robert Gibbs.
4) Rewriting History: The American public has a short memory and liberals count on that to get away with many of their most egregious lies. For example, that's the factor liberals count on when they try to pretend that George Bush lied about WMDs to get us into Iraq. Lies of that sort usually seem to work until someone points out that Democrats, including our current Secretary of State, were saying things like this before the war,
"In the four years since the inspectors left, intelligence reports show that Saddam Hussein has worked to rebuild his chemical and biological weapons stock, his missile delivery capability, and his nuclear program. He has also given aid, comfort, and sanctuary to terrorists, including Al Qaeda members, though there is apparently no evidence of his involvement in the terrible events of September 11, 2001. It is clear, however, that if left unchecked, Saddam Hussein will continue to increase his capacity to wage biological and chemical warfare, and will keep trying to develop nuclear weapons. Should he succeed in that endeavor, he could alter the political and security landscape of the Middle East, which as we know all too well affects American security." -- Hillary Clinton, October 10, 2002
5) Everybody Knows: When liberals want to avoid a losing argument, they sometimes just refuse to have the argument at all and assure everyone that the matter has already been decided. Why, there's no need for Al Gore to even debate global warming with people who could easily blow holes the size of the Grand Canyon in his arguments because he insists that there's a non-existent "scientific consensus."
The Swift Boat Veterans for Truth? As long as the Kerry campaign ignored them, most of the mainstream media did, too, but then the line of attack was immediately that the Swifties had already been "discredited." Who discredited them? How did it happen? What made them less credible than Kerry, particularly since they made him change his story more than once? Whenever you hear liberals in some form or fashion insisting that the argument with conservatives on a particular issue is already over, it's a good indication that they believe they'll really get their clocks cleaned in a straight up debate.
6) The Ransom Note Method: One of the Left's favorite tricks is to take something a conservative says completely out-of-context and to attack that comment, even if it's obvious that they're twisting the meaning of what was said. This is how the Left can accuse John McCain of wanting to fight for 100 years in Iraq or say Rush Limbaugh wants Barack Obama to fail even if it hurts the country.
This one is especially insidious because some conservatives foolishly blame other conservatives for having their words taken out of context. However, the reality is that if someone is determined to distort what you say, he can always find something to twist around. The people who deserve blame in that situation are not the people whose words were misrepresented; it's the liars who have chosen to misrepresent what they said.
7) The Straw Man: If you can't find a sin conservatives have committed to attack, then invent one. This is one of the most used arrows in the quiver of liberals who claim the Right wants to create a theocracy, kick senior citizens off of Social Security, or reward the rich at the expense of the middle class.
The Left uses this tactic against specific politicians as well. Remember during the 2004 campaign when the Left kept promising to fight a draft that Bush didn't propose and didn't support? How about all the attacks on Saxby Chambliss because he supposedly questioned the patriotism of crippled war vet Max Cleland? Except, of course, Saxby Chambliss never questioned Cleland's patriotism.
Unlike liberals, conservatives believe most Americans share our values and so, if you want to know what we think, all you have to do is ask us and we will tell you.