Matt Bai: “Senate Democrats are right to worry that another shutdown might get in the way of that goal. Up to now, absent this shutdown business, Democrats have been looking at a midterm election cycle so promising that even Vladimir Putin couldn’t find a way to rig it.”

“But the longer this standoff looms, the more likely it is that the midterms will become all about immigration. And here the math isn’t nearly so favorable for Democrats, who champion immigration generally but rarely talk about the legitimate anxieties arising from porous borders.”