The Big Question

So the big post-election soul searching among libertarian/conservative folks seems to be, "should I engage in principled opposition or should I give Obama about as much chance as lefties gave George W. Bush?" (e.g. here) Most seem to agree that the former is the way to go, but before this becomes consensus, let me ask "when has graciousness and magnanimity ever been repaid in kind by Democrats and 'progressives'? When? Tell me and I'll be as principled and respectful as anyone.