The deadly assault on the U.S. Capitol on Jan. 6, 2021 shocked viewers watching live around the world and, at least in the moment, infuriated Republican congressional leaders who fulminated among themselves against the role Donald Trump and his allies played in egging on the rioters.

But the short-lived horror over the the worst attack on the seat of U.S. democracy since British troops burned the building in 1814 wasn’t enough to shake the tribal political divisions that drove the insurrection.

As Congress prepares for a series of televised hearings on the assault starting Thursday, polls show the Republican party is on track to make big gains in the U.S. midterm elections, despite fielding candidates who embrace the false narrative of election fraud that fueled the riot and shun efforts to investigate the attack.