It turns out Sam Alito hates the Constitution as much as you thought he did.
Summary
Justice Samuel Alito, a self-described Originalist, has been criticized for allegedly disregarding the Constitution’s text when it conflicts with his personal views.
Recently, it emerged that Alito accepted a knighthood from a European order, despite the Constitution’s ban on foreign titles for U.S. officials.
This title, from the House of Bourbon–Two Sicilies, raises questions about Alito’s commitment to American democratic ideals, which the Framers aimed to protect from foreign influence.
Critics argue that Alito’s actions reflect hypocrisy in his supposed adherence to Originalism and constitutional principles.
Conservative lobbyist and court-packer Leonard Leo belongs to the Sovereign Military Order of the Knights of Malta, a Catholic lay order that dates to the Crusades. The Opus Dei organization, best known for its super-kinky corporal-mortification rules, sent a priest wearing a spiked garter under his cassock to convert a swath of Republicans in Washington — a project that has proved quite successful.)
He does fly this flag at his home, though
It's not because of it's original use.
It's because he's a major player/member in the NAR (the new apostolic reformation) which is an accelerationist movement with the explicit intent to bring about Armageddon so Jesus can return.