Nikki Haley’s campaign may have been the last stand of the Reaganite wing of the GOP against the MAGA takeover, but one conservative said more traditional Republicans must consider doing the unthinkable and back President Joe Biden. Mona Charen, a former White House staffer for Ronald Reagan and now a columnist for The Bulwark, called out another veteran of that presidential administration who lamented the choices in this year’s election and concluded that a principled conservative must reject Trump in favor of a third-party challenger. “The world might look very different if traditional Repub…