Clinton grew up in Hot Springs where Arkancides were common. It also helps explain his use of Lenzner and Palladino as hit men.
Thus, for Gergen to say that Clinton carries no grudges is like saying the Mafia carries no grudges. Gergen must be on retainer to defend Clinton to have made such incredibly false statements in support.
As for O'Reilly, he thinks he can save his ratings if he looks even-handed, even if what he says is unprincipled hogwash.