In the perennial battleground of Wisconsin, Democrats are having a moment. Liberals have their first majority on the state Supreme Court in 15 years. New maps will almost certainly eat into Republicans’ long-standing majorities in the state Legislature, and more favorable congressional lines could follow. The party has a strong incumbent in the U.S. Senate who still doesn’t have a top-tier Republican challenger heading into her re-election campaign this year and an incumbent governor with consistently solid approval ratings.