I think comparisons between the Obama and Biden presidencies will occupy their own niche in the literature. Their differing approaches to Congress, their legislative records (with very different congressional majorities), their judicial appointments - there will be some ink spilled there.
This is right. Obama vs Biden will be the JFK vs LBJ comparison game of yesteryear. (Not really commenting on who's right, even, given that Brandon has 2-6 years left) Biden was Obama's VP and was older, gruffer, never intended to run in his own right, and the consummate insider power player to pair with the fresh-faced young Senator.
Who knows how the comparison turns out, though I suspect it turns out way kinder to Biden if he's reelected. Losing reelection is always a serious failure marking on a President no matter how accomplished his term was otherwise.
