Along with endorsements from local Republican groups, the polls served the tea party-backed candidate's efforts to counter attacks from establishment Republicans such as former Gov. Pete Wilson, Rep. Darrell Issa, R-Vista, and strategist Karl Rove.
On Sunday, however, a USC/Los Angeles Times poll showed Donnelly's GOP rival, Neel Kashkari, ahead of Donnelly by a narrow margin, 18 percent to 13 percent among likely voters.
Donnelly was dismissive.
"The only poll that is going to matter is tomorrow, and we're close enough that I'm not worried about any other polls," Donnelly told reporters at the Capitol on Monday. "And at people's doorsteps, I've discovered that this whole thing is up for grabs, and it's going to be whoever turns out their votes, that's who's going to win."
Kashkari, in a spate of radio interviews Monday, said the poll is evidence his recent spending on mailers and TV ads is paying off.
Before he started advertising, Kashkari said on KGO 810 radio in San Francisco, "most voters had not been paying attention to the race," and all he needed was "to introduce myself to voters."
PHOTO: Tim Donnelly campaigns at the Punjabi American Festival in Yuba City on May 25, 2014. The Sacramento Bee/David Siders