In Missouri, it's Rep. Michele Bachmann vs. Joe the Plumber and the Tea Party.

More than two dozen Missouri Tea Party groups are fuming this week after Bachmann announced she was coming to St. Louis to campaign for Rep. Roy Blunt.

Blunt, a Republican, is running for Senate in Missouri, but some Tea Party groups there have thrown their support behind state Sen. Chuck Purgason in the GOP primary.

Purgason's campaign is definitely a long shot: he's raised $32,000 to Blunt's $8.2 million, according to Federal Election Commission filings.

But Samuel Wurzelbacher, known as "Joe the Plumber," is backing Purgason and has bankrolled an ad that will run in nearly every Missouri TV market, the St. Louis Post-Dispatch reported.

And Missouri Tea Party groups say Bachmann "has been grossly misled" if she thinks Blunt is the "Tea Party candidate."

"Tea Party participants believe the spending in Washington has to STOP," 28 groups wrote in a joint statement. "Roy Blunt voted for TARP and Cash for Clunkers. For Michele Bachmann to come to Missouri and give the impression that all the Missouri Tea Parties support Roy Blunt is an abomination of everything we have been standing up for."

This isn't the first time Bachmann, who leads the Tea Party Caucus in Congress (holding its second meeting today), has been in hot water with tea partiers.

In New Jersey last month, Republican congressional candidate Alan Bateman said Bachmann "sold out the Tea Party movement" after she did a robo-call on behalf of Republican incumbent Rep. Chris Smith.