In a concurring opinion in a Supreme Court case announced Monday, Justice Clarence Thomas issued a lengthy call for his colleagues to overturn "demonstrably erroneous decisions" even if they have been upheld for decades -- prompting legal observers to say Thomas was laying the groundwork to overturn the seminal 1973 case Roe v. Wade, which established a constitutional right to abortion. Thomas' blunt opinion came in Gamble v. United States, a case concerning the so-called "double-jeopardy" doctrine, which generally prohibits an individual from being charged twice for the same crime. But both pro-life and pro-choice advocates quickly noted the implications...