These are the key races to watch in states holding primary elections today

Rev. Gregory Lewis, left, of Milwaukee, drops his ballot in the ballot box while early voting at the Frank P. Zeidler Municipal Building on North Broadway in Milwaukee on Tuesday, July 30. 

Mike De Sisti/The Milwaukee Journal Sentinel/USA Today Network

Connecticut, Vermont, Minnesota, and Wisconsin will hold their primaries for congressional and statewide offices on Tuesday. 

Here are some of the key races to watch for:

• Connecticut will hold two federal primaries: Republican contests for Senate and in the 4th Congressional District. The winners will face Democratic incumbents in November. There will also be some state legislative primaries. 
• Vermont has a full set of primaries Tuesday including for US House and Senate and governor, although almost all the statewide races are uncontested. Independent Sen. Bernie Sanders is unopposed on the Democratic primary ballot, although he historically declines the party’s nomination. 
• In Minnesota, a wide field of Republicans in the state’s Senate primary are vying for a spot in the general election to challenge Sen. Amy Klobuchar, who will be favored to win in November. Rep. Ilhan Omar is looking to win the Democratic primary in Minnesota’s 7th District after two fellow members of the House’s progressive “Squad,” Reps. Jamaal Bowman and Cori Bush lost renomination in recent months. 
• Wisconsin voters will formalize one of the crucial Senate races that could determine partisan control of the chamber. Two-term Democratic Sen. Tammy Baldwin is unopposed in her primary, and Republicans recruited banking executive Eric Hovde to try and unseat her. Hovde faces two challengers but is favored to advance