From Hitler’s spittle-drenched rallies to Tuesday’s State of the Union, the rhythm is familiar: A nation cast as besieged. Enemies within. Purification promised. When grievance becomes spectacle and politics becomes theater, the splash zone widens. The 20th century left us film footage of what this language becomes when it matures. The question lingering in the House chamber — and beyond — is whether these echoes from the past are a warning or a blueprint.