I don’t have a particularly strong take on how the death of Ruth Bader Ginsburg will affect either the presidential election or the race for control of the Senate. And I’d encourage you to avoid putting too much stock in anybody else’s take for now, too. The very earliest indication is that President Trump’s desire to move full-speed ahead toward naming Ginsburg’s replacement could be unpopular, but that’s based on only one poll. But here’s what I do know: the Senate is an enormous problem for Democrats given the current political coalitions, in which Democrats are dominant in cities while...