A 19th century “anti-vice” law is at the center of a new court ruling that threatens access to the leading abortion drug in the U.S. Dormant for a half-century, the Comstock Act is being revived by groups seeking to block the mailing of mifepristone, the pill used in more than half of U.S. abortions. On Friday, a conservative judge in Texas sided with Christian conservatives in ruling that the Comstock Act prohibits sending the long-used drug through the mail. The decision, which will be appealed, is likely to have far-reaching consequences for millions of women, abortion providers and their opponents.