No,no you got it all wrong,throwing someone under the bus just refers to a political figure being dissed,not supported politically, by cronies who otherwise supported him, nothing else. This well could happen to any of the top leaders any time its just politics as usual.
I recall Teddy Kennedy doing it to Carter (but Chappaquidick was his fatal flaw) but that weakened Carter enough for Reagan to beta him; and Bobby Kennedy doing it to LBJ who gave us Hubert Horatio Hornblower Humphrey to face ultimately successful Nixon.
Hum...that’s the ticket! Have them challenge Obama from within and we’ll win.