Republicans suffered setbacks to court challenges over the presidential election in three battleground states on Friday while a law firm that came under fire for its work for President Donald Trump’s campaign withdrew from a major Pennsylvania case. The legal blows began when a federal appeals court rejected an effort to block about 9,300 mail-in ballots that arrived after Election Day in Pennsylvania. The judges noted the “vast disruption” and “unprecedented challenges” facing the nation during the COVID-19 pandemic as they upheld the three-day extension.