A pact made with the Devil—selling one’s soul in order to gain power, knowledge, wealth, beauty, youth, or some other desired goal. The theme is an old one: one may gain short-term delights, but the Devil comes to collect in the end. One must eventually ‘pay the piper’ – bear the consequences.
1.) A pact with Satan in which the initiators soul is exchanged for some worldly desire.
2.) The willingness to sacrifice anything in order to quench a limitless desire for knowledge or power.
For both 1 & 2: John McCain has undermined his past values and reputation as a conscientious independent voice by making a faustian bargain in order to secure the Republican nomination for the 2008 presidential election.