Missouri Secretary of State Jason Kander’s office is forecasting a 31 percent voter turnout in Tuesday’s primary election. Kander cites local election authorities’ voter turnout projections.

The Missouri State Capitol (photo courtesy; Tim Bommel, Missouri House Communications)

The Missouri State Capitol (photo courtesy; Tim Bommel, Missouri House Communications)

Polls in Missouri are open on Tuesday from 6 a.m. to 7 p.m.

Here is a look at some of the key races in Missouri on Tuesday:

** U.S. Senate: Incumbent Senator Roy Blunt (R) faces three primary challengers: Kristi Nichols, Bernie Mowinski and Ryan Luethy. Blunt is seeking his second Senate term. Four Democrats are running: Secretary of State Jason Kander, Chief Wana Dubie, Cori Bush and Robert Mack.

** Gubernatorial race: Governor Jay Nixon (D) cannot seek re-election because of term limits. Four Democrats are seeking the nomination: Attorney General Chris Koster, former Kansas City Mayor and former State Sen. Charles Wheeler, Leonard Steinman II and Eric Morrison. Four Republicans are seeking the GOP nomination: former House Speaker Catherine Hanaway of Warson Woods, Navy SEAL Eric Greitens, businessman John Brunner and Lt. Governor Peter Kinder.

** Lt. Governor: Republican incumbent Peter Kinder (R) is running for Governor, so the Lt. Governor position is open in November. Kinder is finishing his third term. Three Republicans are running: Bev Randles, State Sen. Mike Parson of Bolivar and Arnie Dienoff. Three Democrats are seeking their party’s nomination: former St. Louis Congressman Russ Carnahan, St. Louis State Rep. Tommie Pierson and Winston Apple.

** Secretary of State: incumbent Democrat Jason Kander (D) is running for U.S. Senate, so the Secretary of State position is open in November. Kander was elected in 2012. Three Democrats are running: Bill Clinton Young, former St. Louis television newscaster Robin Smith and MD Rabbi Alam. Three Republicans are running: State Sen. Will Kraus of Lee’s Summit, Jay Ashcroft and Roi Chinn.

** Attorney General: incumbent Chris Koster (D) is making a gubernatorial run, so this position is open in November. Koster is finishing his second term as Attorney General. Two Democrats are running: former State Rep. Jake Zimmerman, D-Olivette, and former Cass County Prosecutor Teresa Hensley. There are two Republican candidates: constitutional lawyer Josh Hawley of Columbia and State Sen. Kurt Schaefer, R-Columbia.

** Missouri’s First Congressional District: incumbent U.S. Rep. Lacy Clay (D) is being challenged by State Sen. Maria Chappelle Nadal, D-University City, and Bill Haas. Clay is in his eighth term in Congress. Two Republicans are seeking the GOP nomination: Steven Bailey of St. Louis and Bridgeton’s Paul Berry III. The First Congressional District includes St. Louis City and parts of St. Louis County.