WASHINGTON — Supreme Court justices tend to wipe the slate clean at the start of a new term, the bruised feelings occasioned by tough cases eased by a summer break.But this year, some justices are engaging in an extended and unusual public disagreement over the court’s legitimacy following the decision to overturn Roe v. Wade.The latest comments came Tuesday night from conservative Justice Samuel Alito, the author of the June decision that took away women’s constitutional protections for abortion. But the …