THE OATH SHOULD BE READMINISTERED.

Who's to say that "strict constructionists" couldn't try to undo presidential actions due to "procedural error"?

Obama should graciously invite Roberts to the White House for a "mulligan."

He can call it a courtesy, a show of respect for those strict constructionists on the court who might argue at a later date that the administration of the oath was invalid.

Such a ceremonial (but, from a strict constructionist point of view, binding) re-do would be putting his opponents on notice that Obama is hip to the potential deployment of faulty phraseology as a political weapon.