Dave Weigel notes that Wisconsin's Supreme Court race was yet another setback for Democrats:
They saw a decent chance to defeat Rebecca Bradley, a conservative justice appointed to the state Supreme Court by Walker. Her opponent, JoAnne Kloppenburg, nearly won a seat on the court in 2011.
…Bradley won the election, a surprise to Democrats. This morning, some progressives picked a culprit: voters who cast ballots for Democratic presidential candidate Sen. Bernie Sanders (Vt.) and left the rest of their ballots blank. According to exit polling conducted by the independent group DecisionDesk and BenchMark Politics, perhaps 15 percent of Sanders voters skipped the Bradley-Kloppenburg race; just 4 percent of Hillary Clinton voters did the same.
Bernie endorsed JoAnne Kloppenburg, so this isn't a matter of him refusing to play ball with anyone running on the Democratic ticket. Nonetheless, it's a serious issue, no matter what you think of Bernie versus Hillary on the issues. Bernie is basing a lot of his campaign not just on anti-Hillary sentiment, but on anti-Democratic-Party-establishment sentiment. That's fair enough, but like it or not, the Democratic Party is all we have to compete with Republicans.
Bernie has been asked before if, for example, he'd raise money for Democrats if he won the nomination, and he responded, "We'll see." That's really not going to cut it anymore. Bernie doesn't have to mindlessly support every Democrat on the ballot, but voters deserve to know what he'd do if he won the Democratic nomination. Would it be all Bernie all the time? Or does he become a fighter for all the down-ballot races Democrats need to win in order to pass all that revolutionary legislation we hear so much about?