Jason Opal, McGill University Just two days after surviving a bloody assassination attempt that claimed the life of one of his supporters, Donald Trump has chosen Ohio Sen. JD Vance as his vice-presidential running mate. That’s a good move. Let’s start, though, with what Vance does not do for Trump, the former president and Republican presidential nominee. Vice-presidential picks sometimes come from hotly contested states in hopes of boosting the ticket in that state. But Ohio has been safely Republican since 2004, so there’s no real gain for Trump in that respect. Vance is not especially asso…