Former eBay CEO Meg Whitman holds a three-point lead over Democrat Jerry Brown in the race for the California governorship, according to a new poll from Rasmussen Reports.

After relying largely on union supporters to keep Whitman at bay through the summer, Brown, who served as the state's governor from 1975-1983, has taken a more active role in campaigning as the fall election approaches. He launched his first TV ad this week and held a rally in Oakland last week.

California Working Families, a union-backed independent expenditure committee, spent $8.7 million hammering Whitman over the summer in an attempt to keep Brown close in the polls as Whitman continued to saturate the airwaves. She has spent $104 million of her own money on the campaign so far.

Brown's supporters succeeded in keeping him within striking distance. Whitman leads Brown 48 percent to 45 percent in the Rasmussen poll, which is down from her 51-43 advantage in the previous Rasmussen poll taken August 24. She leads by a mere 1.3 percentage points in the RCP Average.

While the race remains tight, Whitman's big spending summer seems to have helped her put a dent in Brown's favorability ratings. Thirty-six percent of voters surveyed said they have a very unfavorable view of the former governor. Twenty-eight percent said they view Whitman very unfavorably. Additionally, 55 percent of voters view Whitman either very or somewhat favorably, but only 45 percent say the same for Brown.

For this poll, Rasmussen Reports surveyed 750 likely California voters on Monday. The poll has a margin of error of +/- 4 percent.