A random search on "Obama's lies" results in 8,900 hits, compared to 1,470 for "McCain's lies." Obviously people on the internet are much more likely to think that Obama is a liar.
Last week Obama made a few lies. Obama said that wealthy people did "not ask" for the tax cuts and "do not need it." Obama is a liar because Americans of all stripes have been demanding tax cuts for a very long time and it is not up to him to decide who is in "need" of a tax cuts. By speaking of needs in this way, he seems to be emulating his fan Karl Marx, who spoke of "to each according to his ability, to each according to his need." Are you a communist, Obama? If not, why do you speak in the language of a hard-core communist?