The meme since the NY-23 kerfuffle has been that Republicans will face contested primaries in dozens of their races, and an emboldened tea party movement will give establishment candidates the boot and potentially hand easy wins to the Democrats.
The evidence had been adding up - with tea party candidates popping up in Pennsylvania and Texas and conservative groups targeting moderate Republicans in California and Florida.
But Kirk holds a steady lead in our TPMPolltracker average over two tea party-backed challengers Patrick Hughes and Judge Don Lowery despite all those efforts. Republicans in Washington expect him to emerge the nominee and shake off the tea party fears for the GOP nationwide.
"This blows a hole in that whole narrative," said Brian Walsh, a spokesman for the National Republican Senatorial Campaign Committee.
Walsh said the Democrats have enjoyed painting a picture of a fractured party pulled in different directions by tea party movements, but it's really about whether the candidate with the "R" after his or her name is victorious in November.
He also pointed out there are tough Democratic fights in Pennsylvania, Colorado and Ohio.
As we've reported, Kirk was once a barometer for the middle but has tacked to the right during the primary. Democrats are happy either way - if he loses, they think a tea partier would be easier to defeat and if he wins they will portray him as a flip-flopper in the general election.
With just one day left in the race, TPMDC tracked down tea party organizers in Illinois who all dismissed the polls as not capturing voters' anger or the lack of support Kirk holds downstate.
"If Mark Kirk wins that is okay, that just means we've got a lot more work to do," said Rhonda Linders, an activist with the Alton Tea Party near the Missouri border. "We'll just keep fighthing for the next one, which will be Sen. Dick Durbin in 2014."
Tea party organizer Ralph Sprovier, from a Chicago suburb, said Kirk may win in part because this election was so early in the year and there wasn't enough time to get organized.
"I don't think it's going to give us a true understanding of how powerful the tea parties are, until we get to August when Florida will be choosing between Charlie Crist and Marco Rubio, and when we will for sure have stopped the agenda in Washington."
Sprovier was referring to the Republican primary candidates for Senate, where an insurgent and more conservative Rubio is winning national attention and showing a lot of strength in the polls.
Since everyone in Illinois kept citing Crist-Rubio as the real tea party test, I also checked in with Robert Brown, chairman of the Nassau, Florida Republican Party. He said no one in the Sunshine State is paying attention to Illinois, and also said he hasn't seen much tea party influence on the ground yet.
"These races aren't nationalized," the chairman said.
Though there is little apparent tea party activity, Floridians said Sen. Jim DeMint's Senate Conservatives Fund has swayed voters by backing Rubio as the true conservative over Crist, who has been criticized for supporting President Obama.
Tea partiers say they are emboldened by the Massachusetts win - where national tea party organizations flooded the state with money and manpower for Republican Scott Brown - but Brown himself cautioned against drawing significance from his victory.
"You are making an assumption that the Tea Party movement was influential, and I have to respectfully disagree. It was everybody. I had a plurality," Brown (R-MA) said on ABC's "This Week" on Sunday.
Another detail comes in the form of a new poll Evan reported on yesterday:
Though the numbers would seem to bode well for the GOP, which is more closely aligned with Tea Party than the Democrats are, the poll could actually cause heartburn for Republicans hoping for big victories this fall. When lined up against a Democrat and a Republican on a generic congressional ballot, 8% said they'd pull the lever for a third, Tea Party candidate enough to give the Democrats the win in a three-way race. The Democrats won the hypothetical matchup 31-26-8, with 35% undecided.
In a twist, the Illinois tea partiers have hope that Adam Andrzejewski, their candidate for the Republican nomination for governor, could pull out a victory today. He was endorsed by conservative commentators Glenn Beck and Rush Limbaugh and has gained in recent polling, though he still trails the other candidates.