This is just depressing: Six months since the House committee investigating the Jan. 6, 2021, assault on the Capitol completed its work, a far-right ecosystem of true believers has embraced “J6” as the animating force of their lives. They attend the criminal trials of the more prominent rioters charged in the attack. They gather to pray and sing “The Star-Spangled Banner” on the outer perimeter of the District of Columbia jail, where some two dozen defendants are held. Last week, dozens showed up at an unofficial House hearing convened by a handful of Republican lawmakers to challenge “the fake narrative that an insurrection had occurred on Jan. 6,” as set forth by Jeffrey Clark, a witness at the hearing and a former Justice Department official who worked to undo the results of the 2020 election. The 90-minute event was a through-the-looking-glass alternative to the damning case against former President Donald J. Trump presented last year by the Jan. 6 committee. In the version advanced by five House Republicans who attended the hearing — Matt Gaetz, Paul Gosar, Ralph Norman, Marjorie Taylor Greene and Troy Nehls — as well as conservative lawyers and Capitol riot defendants, Jan. 6 was an elaborate setup to entrap peaceful Trump supporters, followed by a continuing Biden administration campaign to imprison and torment innocent conservatives. Writ large, their loudest-in-the-room tale of persecution rather than prosecution might be dismissed as fringe nonsense had it not migrated so swiftly to the heart of presidential politics. Mr. Trump has…