"The rules have changed and the political ground has shifted under the feet of the establishment and they are still trying to get their footing," Mike Connolly of the conservative Club for Growth told me in an interview today. The group was backing outsider candidates before it was cool, encouraging contested primaries by running Pat Toomey (R-PA) against Sen. Arlen Specter in 2004.
In many cases, DeMint's candidates seem to be prevailing. For example, Rubio has won more than two dozen Florida straw polls over Crist, who is being targeted in part for supporting President Obama's stimulus plan last year.
The current TPM Poll Average of this race shows Rubio with 56.9% and Crist with 28.5%.
Last weekend Colorado Republican Jane Norton - dubbed the mainstream candidate by conservatives - lost a straw poll to Ken Buck.
Straw polls sometimes indicate where candidates have both momentum and strength on the ground. Another test to keep an eye out for - the caucus in Colorado next week where Norton's campaign aims to outperform Buck.
Former Sen. Dan Coats (R-IN), a top recruit to run for the seat Sen. Evan Bayh is vacating, came in last in a very small straw poll conducted by a tea party group backing the candidate who prevailed, State Sen. Marlin Stutzman. (See poll data on this race, which is still shaping up, here.)
Sue Lowden (R-NV) has yet to win a straw poll. In this case, Senate Majority Leader Harry Reid (D-NV) trails all of his potential Republican challengers.
Senate Conservatives Fund candidate Chuck DeVore won a California straw poll over the NRSC's preferred candidate former Hewlett Packard executive Carly Fiorina, though the legitimacy of the poll has been called into question.
Fiorina seems to be in trouble. The current TPM Poll Average of the California race shows Tom Campbell with 31.0%, Fiorina with 20.0% and DeVore with 8.7%.
"These challengers are closer to the general mood of country and the tea party," Connolly said of the non-NRSC contenders. "The Republican Party belongs to Republican voters, not just to the Republican leaders in Washington. Contested primaries help us see where the party is before November."
NRSC spokesman Brian Walsh declined to comment on specific state primaries and said the group's primary goal is to defeat Democrats this fall.
"Any campaign operative who puts full faith in straw polls is going to have a short career in politics," he told me. Case in point, Ron Paul won the CPAC presidential straw poll last month (and numerous polls in 2008) but is highly unlikely to be the Republican nominee in 2012.
In recent weeks the GOP has embraced the challenges, with speakers at the Tea Party Nation convention and the Conservative Political Action Conference lauding competitive primaries and saying it's okay if incumbents get the boot. The Club for Growth says they want to defeat Sen. Bob Bennett, who faces Republican challengers this month in Utah.
Red State's Erick Erickson is helping DeMint's Conservatives Fund. Last night Erickson took to his Twitter feed to say the Bennett race is a warning to another GOPer not up for reelection until 2014.
"Another reason to beat Bob Bennett: send Lindsey Graham a credible message that he is next," wrote Erickson, whose motto is "We fight the left and clean up the right."
The NRSC's Walsh said Democrats have plenty of "very real problems within their own party."
"If this is a narrative Democrats want to push than I look forward to hearing Arlen Specter's reaction to that considering his big loss to Joe Sestak at last year's Netroots Nation conference in Pittsburgh," Walsh told me. "[W]hile Democrats try to distract folks by talking about GOP primaries, the reality is that they're not only losing in at least 6 seats currently held by Democrat Senators, but three of their incumbents are facing very serious primary challenges."