St. Louis (KSDK) -- Missouri's primary election has a number of notable match-ups.
Todd Akin, John Brunner and Sarah Steelman are the three front-runners on the Republican ballot for US Senate.
"This seat is critical to controlling the United States Senate," says NewsChannel 5 Political Analyst Dave Robertson.
He calls this match-up the marquee race this primary. A close contest and lots of money spent for a valuable nomination. Whoever wins, he says, could help upset the democrat controlled senate, if he or she can beat Incumbent Democrat Claire McCaskill.
"This year she's very vulnerable because she's tied to an agenda that's not terribly popular in Missouri, the Obama administration and the affordable care act and the stimulus program," said Robertson.
On the Carnahan/Clay congressional race, NewsChannel 5's exclusive Survey USA Poll show's Clay with a comfortable lead but, despite the outcome, Robertson says the candidates who once worked together would do well to repair their relationship.
"You know that it's going to be a huge challenge to sort of patch up the party in the city of St. Louis and St. Louis County to try to bring the party back together," said Robertson.
There are six other candidates running for the US Senate seat.
The five other republican candidates are:
Mark Patrick Lodes
There is one Libertarian candidate named Jonathan Dine.
Robertson says another big issue on the primary ballot is Amendment 2. That's the measure that protects the right of kids to pray in school. He expects it will pass.
NewsChannel 5 is your home for the primary election coverage.
We'll have live team coverage starting at 10 p.m. Tuesday on KDNL ABC 30.
Then again on NewsChannel 5 at 11 after the olympics.
And you can get up to the minute results on KSDK.COM throughout the night.