Each election cycle, thousands of eligible voters are effectively disenfranchised because they sit in a jail cell. Americans detained before trials are allowed to vote, a status affirmed by a 1974 Supreme Court case. As a matter of law, pretrial detainees are presumed innocent and retain the voting rights they had before being charged with a crime. Yet people in jail face significant, sometimes insurmountable obstacles to registering to vote and accessing a ballot. Advocates say that this “de facto disenfranchisement” affects the majority of the roughly 445,000 people in American jails who hav…