WASHINGTON-Sen. Joseph Biden’s new role as vice presidential running mate immediately revives a debate over whether Catholic politicians who support abortion rights should receive Communion. The senator chosen by Democratic candidate Sen. Barack Obama regularly attends a Greenville, Del., Catholic church and-while disagreeing with his church’s stance on abortion-is known for supporting other key tenets of the Catholic faith. “He’s very committed to helping working-class folks and poor people, and that’s what Catholic social teaching is all about,” said the Rev. Thomas Reese, senior fellow of the Woodstock Theological Center at Georgetown University in Washington.