At a series of fundraisers in San Francisco, the Democrat acknowledged he has had a tough first three years in office and asked supporters to summon the energy to mobilize for him again to complete unfinished business on his agenda. "We're going to have to be as focused as we were in 2008," he said, joking that it was "not as trendy" to support him now as when he first emerged as a presidential candidate, but also noting the economic downturn has dampened spirits. "We've gone through three tough years and so people want to hope, but they've been worn down by a lot of hardship," he told 70 people who paid $35,800 each to attend a dinner that included a live performance from soul singer Al Green. He said his second-term to-do list included making sure health care and Wall Street reforms were fully implemented, continuing to bolster education and scientific research, and advancing US oil, gas and clean energy production. He also pitched items of interest but left unattended in his first term, including addressing the large numbers of undocumented workers in the United States and facing down global warming. "We've still got to get immigration reform done, because we are a nation of immigrants and we are a nation of laws," he said, adding: "We're going to deal with climate change in a serious way." "And we're going to have to figure out how to pay for all this stuff," Obama said, saying that wealthier Americans - like him and like them, in his words - "can do a little bit more to make sure that kid around the corner has a chance like we did." California's economy is the biggest among the US states and is the ninth-largest in the world, ahead of India, Canada, Russia and Spain. Obama has been courting support from both Hollywood and the California tech sector as the election year is underway. He is expected to raise $8 million in six fundraising events in California the first was in Los Angeles on Wednesday night plus two in the Seattle area on Friday.