A case that the Supreme Court just agreed to hear is a crucial turning point in the American conservative movement’s ability to assert that black is white and up is down, David Roberts recently argued in a stream of tweets. The case, sometimes referred to as “Halbig,” is a legal challenge to Obamacare. It asserts that, by virtue of what amounts to a typo — one section of the law carelessly refers to “an Exchange established by the State” — health insurance exchanges must be established by states in order to offer premium subsidies, i.e., federally established exchanges can’t offer such subsidies. That is an inversion of what the law’s authors intended. If the court sides with the plaintiffs, Obamacare will be crippled.