When a politician outright lies to the public on policy when they know they are going to change position once elected or when the wind blows the other way.
George H.W. Bush (1988): "Read my lips, no new taxes."
George H.W. Bush (1990): "Um... yea.... about that tax thing..."
American Electorate: "WTF? A politician lie!?"
Sarah Palin (2006): "We need this Gravina Bridge for the prosperity of all Alaskans!"
Sarah Palin (2008): "I told Congress, thanks but no thanks on that bridge to nowhere"
American Electorate (2008): "I'm not falling for this Trojan Moose again!"