Supreme Court Justice Samuel Alito’s explanation for why a MAGA election denial upside-down flag was displayed at his house was completely unhinged, legal reporter Mark Joseph Stern told MSNBC’s Alex Wagner on Friday evening — and his attempt to pin it all on his wife having a dispute over an anti-Trump sign with their neighbor was completely unconvincing. Wagner opened with a passage from Stern’s latest article for Slate, which read, “The sheer pettiness of these gripes — the fact that these men continue to filter justice through their small, round, grudge-colored glasses — is what is breatht…