Just how involved did the Catholic Diocese of Pittsburgh get in the effort to promote vouchers? Very, the Washington Post reports. This is clear in an Oct. 20 letter [1] that Dr. Ronald R. Bowes, assistant superintendent for policy and development in the diocese, wrote in October to Catholic school principals. It calls for them to be “relentless” in promoting school choice, in part by telling parents who had received financial aid that they had to call their state legislators and push for school choice legislation to receive more financial aid the next year. Other diocese officials disavowed the letter a few weeks later, according to the Pittsburgh Post-Gazette. Another letter was sent out Nov. 16 saying that Bowes had misstated policy about financial aid…