The latest battle over the Democratic ideological divide this year shifts to the upper Midwest on Tuesday as nominating contests for governor in Wisconsin and U.S. senator in Minnesota pit left-wing candidates against more traditional ones.In Wisconsin, state Rep. Francesca Hong, a self-described democratic socialist, is the front-runner for the party’s nomination for governor in a swing state where winning the governor’s mansion is central to Democrats’ hopes for 2028 and beyond. In Minnesota, Lt. Gov. Peggy Flanagan is running for the nomination for an open Senate seat against centrist Democratic Rep. Angie Craig.The left vs. center theme is on display in Democratic primaries in multiple states voting Tuesday, with other significant races in places like Alabama and South Carolina.Here’s what to watch Tuesday night.Does the left keep surging in swing states? Left-leaning candidates have consistently won primaries, capitalizing on Democratic voter frustration at party leadership. Most wins came in reliably liberal urban areas, ranging from New York Cityto Denver. But last week, progressive candidate Abdul El-Sayed broke new ground by winning the party’s nomination for a competitive Senate race in swing state Michigan.