Missouri Auditor Tom Schweich has decided not to enter the Republican race against Democratic Sen. Claire McCaskill.
Schweich said in a statement Tuesday that he determined his candidacy would have made the Republican Senate primary more contentious, and thus would not have helped Republican chances of defeating McCaskill in November.
The Senate race already includes three prominent Republicans - former State Treasurer Sarah Steelman, U.S. Rep. Todd Akin and businessman John Brunner.
Overcoming a late surge of tea party backing for his opponent, U.S. Sen. Roy Blunt, R-Mo., was elected to the No. 5 Senate leadership post Tuesday in a close vote that pitted an experienced GOP leader against an "outsider" businessman.