With fireworks and calls to action, Republicans running to oust Democratic U.S. Sen. Al Franken appealed to party faithful for support on Friday.
Nearly 2,000 GOP delegates will decide who will best serve them in the fight to unseat the first statewide Democratic incumbent for a generation.
For months, Republican state Sen. Julianne Ortman, businessman Mike McFadden, St. Louis County Commissioner Chris Dahlberg and state Rep. Jim Abeler and others have been traveling the state, organizing their campaigns for delegates and voters.
For some Friday's decision will end the fight -- both Ortman and Dahlberg have pledged to drop out if Republicans do not pick them.
Ortman's campaign handed out a flier to delegates decrying the decision of other candidates not to do so.
"McFadden and Abeler will not respect your vote," her campaign told delegates. "They refuse to abide by your endorsement."
Her campaign, with endorsements from Sarah Palin and national Tea Party groups, has pitched Ortman as the conservative choice for senate. But Ortman, who was challenged from the right in her late state senate run, had not closed the deal with some.
McFadden, who has never run for office before and had little public involvement in GOP politics, told Republicans he was the most electable. McFadden, who will run in a primary whether or not delegates pick him, has told the activists he also has a crucial ingredient other candidates lack: "The money."