(CBS) -- Voters headed to the polls Tuesday night in Connecticut, Vermont, Minnesota and Wisconsin, as the 2018 calendar barrels ahead toward November.
The most closely watched races will be in Minnesota and Wisconsin, where there are competitive House and gubernatorial races. Polls in Tuesday night's races begin closing at 7 p.m., and the final polls close at 9 p.m. Eastern.
Connecticut has closed primaries - meaning the only people who can vote in its Democratic and Republican primaries are those who are registered with that party. Polls close at 8 p.m.
Businessman Ned Lamont has won the Democratic primary for governor, the Associated Press reports. Matthew Corey, a Navy veteran and businessman, won the Republican primary.
On the Democratic ballot, voters chose between Mayor Joe Ganim and Lamont. Ganim was Mayor of Bridgeport from 1991 to 2003, when he resigned after being convicted on corruption charges. He then launched a remarkable political comeback after serving seven years of a nine-year prison sentence, becoming Bridgeport's mayor once again in 2015.
Although Danbury Mayor Mark Boughton won the endorsement of the state's Republican party, he unsuccessfully ran against a number of other business leaders for the nomination.
Other races to watch include the Democratic and Republican primaries for the opening seat in Connecticut's 5th Congressional District. Rep. Elizabeth Esty, a Democrat, is not seeking a fourth term.
Sen. Bernie Sanders has easily won Vermont's Democratic primary, according to the Associated Press. However, Sanders is expected to turn down the nomination, as he has in the past, and continue serving as an independent.
Incumbent Gov. Phil Scott won the Republican nomination for governor.
Four Democratic candidates and two Republican candidates are vying for the Vermont governor seat. On the Republican side, incumbent Gov. Phil Scott secured his party's nomination once again.
Scott's popularity in the state has dropped since he signed gun control laws in April. A Morning Consult poll from July found that Scott had an approval rating of 47 percent, a 38 point drop in approval since May 2016. Businessman Keith Stern challenged Scott from the right.
Through a loophole in Vermont's laws, 14-year-old Ethan Sonneborn is running for the office as a Democrat. Vermont's Constitution doesn't have an age requirement, it just requires candidates to have lived in the state for four years.
"I think Vermonters should take me seriously because I have practical progressive ideas, and I happen to be 14, not the other way around," the 14-year-old said in a recent gubernatorial forum. "I think that my message and my platform transcend age."
Sonneborn spoke with CBS News reporter Ed O'Keefe about his candidacy.
Another notable candidate vying for the Democratic nomination in the gubernatorial race is Christine Hallquist, who would be the nation's first transgender governor if successful Tuesday, and in November.
Hallquist said in an interview with "Red & Blue" on CBSN that she was confident she would win the primary.
"Vermonters are going to elect me for what I'm going to do for Vermont," Hallquist said. "Vermont has always been a leader in civil rights. We have some of the best transgender protection laws in the country. It's a state that's really welcomed me with open arms."
In the Senate race, Sen. Bernie Sanders is seeking the Democratic nomination, although he plans to run for reelection as an independent come November. Sanders is expected to easily clinch the Democratic nomination.
The departure of former Sen. Al Franken means both of the state's Senate seats are up for grabs this fall. Franken left office in January amid #MeToo allegations.
Running for Franken's open seat are former George W. Bush ethics lawyer Richard Painter, and current Sen. Tina Smith, who was appointed to take Franken's seat. Sen. Amy Klobuchar, a Democrat, is also running for the Democratic nomination to keep her seat.
In the gubernatorial race, former Republican Gov. Tim Pawlenty is seeking his party's nomination.
Also of interest in the state is the race for attorney general, after Rep. Keith Ellison, one of the Democrats vying for his party's nomination, was accused of abuse by a former girlfriend. Ellison has denied the allegation. Ellison is currently the deputy chair of the Democratic National Committee.
In Minnesota's very competitive 2nd District in the suburbs of Minneapolis and St. Paul, incumbent Republican Rep. Jason Lewis is facing a slew of controversy over comments he made on a radio show he hosted prior to serving in Congress, including complaining that women could no longer be called "sluts" and equating gay marriage to rape.
Polls close at 9 p.m. Eastern, or 8 p.m. local time.
Kansas Gov. Jeff Colyer conceded to Kris Kobach in the Republican primary on Tuesday night. Kobach, the current secretary of state, held a slim lead over Colyer on election night Aug. 7. Provisional ballots counted after election night did not find enough votes for Colyer to overcome a deficit of 110 votes at the time of poll closing, out of more than 311,000 votes initially counted.
Colyer said he would endorse Kobach for governor.
Democrats have so far been unable to unseat Republican Gov. Scott Walker, but they hope to come November. Walker prevailed in a recall election in 2012 and then again in 2014.
But Walker has a race of his own to contend with Tuesday night, as he strives to clinch the Republican nomination against Robert Meyer.
The Democratic field in the race for governor is a crowded one, with eight contenders. Tony Evers, the state's superintendent of public instruction, is expected to have the best shot.
Meanwhile, Democratic Sen. Tammy Baldwin will likely face off in November against one of two top GOP hopefuls, Kevin Nicholson or Leah Vukmir.
Several candidates are also seeking to fill House Speaker Paul Ryan's congressional seat, as he is not running for re-election. Ryan has endorsed his former staffer, University of Wisconsin regent Bryan Steil, in the five-way Republican primary. Paul Nehlen, the controversial candidate who unsuccessfully ran against Ryan in 2016, is also running for the seat. On the Democratic side, Randy Bryce has the support of the local party. However, he has a history of arrests, including one for driving while intoxicated in 1998.