Nikki Haley is the latest, but it’s a tight contest as to who is the most craven and cynical of countless Republican Party officeholders who have forsaken all principle and moral authority in embracing a failed insurrectionist and would-be despot who has lied, evaded, bluffed and bullied his way into position to perhaps retake the presidency come November. Haley’s recent capitulation and endorsement of Donald Trump, whom she correctly and righteously eviscerated as unfit for office over many months on the campaign trail, is particularly glaring on this Memorial Day weekend, when courage and self-sacrifice are held up as the ideals…