For much of the last two years, the Missouri Senate has been mired in Republican infighting.
On one side is GOP leadership, who have struggled to advance a legislative agenda despite controlling 24 of the chamber's 34 seats. On the other is the conservative caucus, which spent most of the 2022 legislative session throwing up procedural roadblocks and grinding the chamber to a halt.
Whether this dynamic will continue into the future could be decided Tuesday, when voters head to the polls to cast ballots in the primary election. While there are Democrats filed in seven of the 10 contests, the districts in past elections have been solidly Republican, making the primary winner likely to prevail in November.
Both sides of the Senate fight have lined up behind candidates in key GOP primaries across the state. Joining the fray this year is Missouri Right to Life, the state's largest anti-abortion organization, which threw in its lot with the conservative caucus and decided to endorse challengers to incumbent Republicans in several primaries.
And the battle lines aren't always so clear. In most races, the candidates differ little on the issues. In one, a candidate has won support from both sides of the Senate divide.
Here are 10 Republican primaries that could decide the fate of the Missouri Senate next year.
State Sen. Bob Onder is leaving office because of term limits. And the open seat has turned into a showdown between two GOP state representatives from O'Fallon: Nick Schroer and John Wiemann.
Schroer has made it clear his intention is to join the conservative caucus. The political action committee set up to support his candidacy -- called the 1776 PAC -- received $25,000 from 100 PAC, which is aligned with the conservative caucus. He also won the endorsement of Missouri Right to Life.
Wiemann is more aligned with party leadership, having previously served as speaker pro tem in the House. JW Leadership Fund, a PAC supporting his candidacy, has gotten contributions from traditionally Republican groups like the Missouri Soybean Association, but also received $150,000 from the carpenters union.
Incumbent Sen. Mike Cierpiot of Lee's Summit is trying to fend off two challengers from his right -- Rachl Aguirre of Lee's Summit and Joe Nicola of Grain Valley.
Cierpiot is seeking his second term in the Senate after serving seven years in the Missouri House. He raised and spent far more than either of his rivals for the nomination. But he suffered a setback when Missouri Right to Life refused to endorse him, instead giving their seal of approval to both Aguirre and Nicola.
While still favored to win, given how rare it is for Missourians to kick out legislative incumbents, Cierpiot has taken nothing for granted, spending $57,000 directly attacking Nicola.
State Sen. Jeannie Riddle is leaving office because of term limits, inspiring five candidates to jump into the GOP primary.
Two current state representatives -- Travis Fitzwater of Fulton and Jeff Porter of Montgomery City -- along with former state Rep. Bryan Spencer of Wentzville quickly joined the race. They were joined by Mike Carter, a judge from Wentzville, and Joshua Price, who runs an auto shop in Mexico, Missouri.
Carter, Fitzwater and Spencer are considered the frontrunners for the nomination.
Carter, who previously ran for lieutenant governor twice -- once as a Democrat and once as a Republican -- gave his campaign a big boost by cutting himself a $500,000 check in April. His campaign has spent nearly all of that money, though the PAC supporting his candidacy, Shield PAC, has $330,000 cash on hand.
Fitzwater was first elected to the Missouri House in 2014. He won the endorsement of Riddle and has the support of the Missouri Federation for Children, a school-choice advocacy group that has spent nearly $150,000 supporting Fitzwater and opposing Carter. Fitzwater also won support from RightPath PAC, which is widely seen as an effort to thwart conservative caucus candidates.
Spencer won the coveted Missouri Right to Life endorsement and has garnered support from the libertarian-leaning PAC Make Liberty Win. He has courted the conservative caucus, specifically 100 PAC, but hasn't received any contributions. In July, his campaign reported it spent more than $100,000 on direct mail.
Three candidates are vying to replace Sen. Dan Hegeman, who is leaving because of term limits -- former state Rep. Delus Johnson and current state Reps. Rusty Black and J. Eggleston.
Black, of Chillicothe, is considered the frontrunner. He's received support -- indirectly -- from RightPath, which donated $85,000 to Aegis PAC in June, which in turn has spent roughly $55,000 in support of Black. A PAC set up to support his candidacy, called Great Northwest PAC, has spent $80,000 attacking Eggleston and $8,000 attacking Johnson.
Eggleston, of Maysville, has nearly $200,000 cash on hand but has barely spent anything over the last few months.
Johnson, of St. Joseph, earned the Missouri Right to Life endorsement. He appears to be largely self-funding his campaign, kicking in $70,000 of his own money so far.
Incumbent Sen. Justin Brown of Rolla is facing off with state Rep. Suzie Pollock of Lebanon in the seat he won after his father held it for eight years.
Pollock is considered the conservative caucus' pick for the seat, though that hasn't translated to financial support for her candidacy.
She's been badly outspent by Brown, who between his campaign committee and the PAC supporting him, called JB PAC, has poured more than $350,000 into the race in recent months compared to only $30,000 by Pollock.
Brown has also won support from Senate GOP leadership, with Senate Majority Leader Caleb Rowden's PAC giving him $17,000.
State Sen. Eric Burlison is giving up the seat to run for Congress, setting up a showdown between state Rep. Curtis Trent and businessman Brian Gelner.
Both men reside in Springfield. And both are spending big to win the seat. Between the candidates themselves and the PACs supporting them, each has spent nearly $400,000 in recent months.
But Trent won both the endorsement of Missouri Right to Life and support from RightPath, which donated $75,000 to Gladius PAC, which then spent more than $100,000 to support Trent and oppose Gelner.
Trent is also being aided by $50,000 in spending by Rusty Black's Great Northwest PAC.
Perhaps the most unpredictable of the Senate primaries, the race to replace term-limited Sen. Paul Wieland attracted four GOP candidates.
State Rep. Dan Shaul of Imperial has won much of the establishment Republican support, including an endorsement from House Speaker Rob Vescovo, who lives in the district and briefly flirted with running himself.
State Rep. Mary Elizabeth Coleman is the pick of the conservative caucus, with $70,000 in donations from 100 PAC.
State Rep. Shane Roden has badly trailed in fundraising and is considered a longshot in the race.
The wildcard is Jeff Roorda, who served as a Democratic state representative in the district and was defeated by Wieland for the state Senate seat eight years ago. He also ran unsuccessfully as a Democrat for Jefferson County Council and county executive.
Roorda became a lightning rod for controversy, thanks to his role as the public face of the St. Louis police union. The PAC supporting his candidacy, called JEFF PAC, has received more than $240,000 in donations from labor unions. But he's also seen more than $110,000 spent opposing his candidacy by school choice advocates at the Missouri Federation for Children.
Five candidates are hoping to replace term-limited Senate President Pro Tem Dave Schatz. The three considered the top contenders are restaurant owner Ben Brown, businessman Bob Jones and state Rep. Nate Tate.
Both Jones and Brown won a Missouri Right to LIfe endorsement, while Tate has gotten $125,000 in support from organized labor.
Brown is the conservative caucus' preferred candidate, with 100 PAC chipping in $180,000 to the political action committee supporting his candidacy, called BB Freedom Fund. Meanwhile, Jones has benefited from $30,000 in donations connected to Greg Hoberock, the influential GOP donor who resides in the district and is a member of the University of Missouri Board of Curators.
Incumbent Sen. Lincoln Hough, a regular target of conservative caucus scorn, is trying to fend off a challenger from his right from former Springfield City Councilor Angela Romine.
Hough, who is in line to become chairman of the powerful Senate appropriations committee, has vastly outspent Romine. Between his campaign committee and the PAC set up to support his candidacy, called Lincoln PAC, Hough has benefited from more than $450,000 in spending in the race.
Romine has spent less than $20,000, though she has received around $15,000 in support from the libertarian-leaning PAC Make Liberty Win. She also won the endorsement of Missouri Right to Life.
Incumbent Sen. Bill White of Joplin is facing off with Jill White of Granby in his effort to win a second term.
White, an attorney who previously served eight years in the Missouri House, has spent nearly six times as much as Romine, between his candidate committee and the PAC supporting him, called Southwest Missouri Patriot PAC.
RightPath chipped in $10,000 to support White's candidacy.
Carter has benefited from both an endorsement from Missouri Right to Life and $18,000 in spending on her behalf by Make Liberty Win.
A PAC called Missouri Leadership Fund recently dropped $30,000 into the race to oppose White. Among its biggest donors is Missouri Senate Leadership PAC, which is affiliated with conservative caucus member Sen. Bob Onder.
The Missouri Independent, www.missouriindependent.com, is a nonprofit, nonpartisan news organization covering state government and its impact on Missourians.