Pennsylvania GOP state senators' refuse to seat Democrat who had won reelection

Despite the fact the election results in the 45th Senatorial District have been certified by the secretary of state, Senate Republicans took matters into their own hands, and citing a technical rule, they announced Monday that they wouldn’t seat Brewster.

Eventually, all senators but Brewster were sworn in. The voters of the 45th District don’t have a state senator, despite a certified election winner.

Is this not treason? The fall of democracy in plain view and there's barely any coverage on the matter.