Drivers heading north on Keystone Avenue honked as they crossed into the battleground of Hamilton County, one of the "doughnut counties" ringing Indianapolis and populated with "Lugar Republicans" who are seen as a key voting bloc. A handful of drivers stopped at the light rolled down their windows and booed at the group or yelled "Obama!"
Hoosiers for Conservative Senate had knocked on 200,000 doors and distributed 60,000 yard signs, according to co-founder Greg Fettig. The group is working with FreedomWorks for America, a national tea party group run by former House Majority Leader Dick Armey.
The race between Mourdock and Democrat Joe Donnelly had been close since May, when Mourdock and his tea party backers upset U.S. Sen. Richard Lugar by more than 20 points in the Republican primary. That appeared to change, however, after Mourdock said in a debate that pregnancy resulting from a rape is something that "God intended."
The Mourdock supporters said a recent poll showing Donnelly took a significant lead after the comment only made them more fired up.
"I think people just mess around with the numbers. We don't really believe Joe Donnelly has that kind of lead," Mary Ann Burke said, a tea party volunteer. "I don't believe those polls at all."
Burke said she didn't trust Brian Howey, the sponsor of the poll with DePauw University, because he supported Lugar in the primary. Howey has addressed those critiques on his website by arguing his admitted bias has nothing to do with how the poll was conducted.
Indiana Democratic Chairman Dan Parker said Sunday that the Mourdock campaign has been attacking pollsters in recent days. "Campaigns that are behind usually fight about the poll numbers," Parker said.
Tuesday's election will test whether Indiana's tea party supporters can succeed where groups in Delaware, Nevada and Colorado failed in 2010. Mainstream Republicans blamed those losses on tea party backed candidates who made critical mistakes and opened opportunities that Democrats capitalized on.
If Mourdock loses Tuesday it will be in part because of his many mistakes that have been re-played by Democrats ad infinitum and will likely cost Republicans control of the Senate again.
In trying to make a case for his re-election last year, Lugar had said tea party candidates who ousted more electable moderate Republicans cost his party control of the Senate in the last election.
Kristin Minor, a maternity services worker who joined the tea party because of her anger with the health care overhaul said it would be incorrect to lay the blame for a Mourdock loss at the tea party's feet, even though she expects the group will be scapegoated.
"I think that with any loss of anything there needs to be a scapegoat, and I think the tea party is ripe for that," Minor said. "I don't think it will stop us, I think the sleeping giant has awakened across the country."
For Indiana's tea party umbrella group, knocking out Lugar was the relatively easy part. Fettig pointed out that he and Monica Boyer formed Hoosiers for Conservative Senate in the wake of a 2010 election which saw U.S. Sen. Dan Coats win a Republican primary because numerous candidates split the tea party vote.
They coalesced behind Mourdock and carried him through the primary, with a big hand from the anti-tax Club for Growth, which spent heavily on-air in the primary. But the general election battle has brought in a new dynamic, including a more active Republican establishment and a more disciplined campaign from Democrats. And Donnelly is poised for an upset Tuesday as a result.
Boyer said Sunday she was still confident the tea party can deliver Indiana on Tuesday, despite what any poll says.
"We work as if we're 50 percent behind, whether we're ahead or behind," she said.