What we mean is that George W. Bush, while President of the United States of America and beforehand, knowingly and intentionally told untruths, both directly and indirectly, to the public at large.
I expect Obama has done the same. Get used to it. All politicians are liars. As Bill Hicks said, all governments are liars and murderers. End of story.
Aussie perspective: Very recently, radio shock jock Alan Jones said, at a university Liberal Party* club dinner, that Prime Minister Julia Gillard's late father died of shame because his daughter was a liar. She is a liar, but the comment was inappropriate and hipocritical of Jones, who was exposed illegally advertising on his show, an incident we know as the Cash for Comment scandal. Some called for him to be fired, which would have been horrid, but he wasn't and we are doing it democratically by boycotting and emailing his show's advertisers - actions he calls terrorism, highlighting his idiocy for the world. Liberal Party leader Tony Abbot has since repeatedly said the government should die of shame, just today claiming he was oblivious.
Well, look at that. Everyone involved is a damn liar and a useless whingeing sook to boot.
*In Australia, the Liberals occupy the mainstream far-right position, similar to the Republicans in the US. They started as traditionally liberal, but have consistently moved right since then, especially under John Howard, who idolised GWB, as PM. Labor (who for some reason spell their name the American way) are much like the UK's Labour Party: originally socialist, now centrist and drifting further right.