KENOSHA, Wisc. — Want to know just how important Wisconsin is in the midterm election? Take a look at the political luminaries who visited over the last six days. Sen. Kamala Harris on Sunday. Sen. Bernie Sanders on Monday. President Donald Trump on Wednesday. And, the biggest prize of all for Democrats, former President Barack Obama on Friday. With a tight contest for Speaker Paul Ryan’s open congressional seat, a competitive Senate race and a battle for governor that is about as close as it can get, the state that slipped through Democrats’ hands in the 2016 presidential election is getting obsessive attention from both parties in the run-up to Election Day.