Pennsylvania State Capital Bureau In the six weeks that followed a deadly insurrection at the U.S. Capitol on Jan. 6, more than 22,000 Pennsylvania Republicans left their party. About 10,500 of them registered as Democrats, and another 11,600 registered with an unaffiliated party, according to Department of State data. It's likely welcome news to Pennsylvania Democrats, who have watched their registration edge dwindle from about 800,000 in 2018 to a little more than 600,000 last month. Republicans are switching to Democrats mostly in Philadelphia and its surrounding suburban counties, the Lehigh Valley and Allegheny County. Those areas helped Democrats win the 2018 midterms and 2020 presidential election, and higher margins could encourage Democrats.