SAN FRANCISCO - President Barack Obama on Saturday wrapped up a week that saw him raise campaign money for Democrats on both coasts.

Obama attended a "round table" discussion at the home of Democratic donor and Zynga founder Mark Pincus and his wife, Ali, with about 25 supporters who paid up to $32,400 for the privilege, according to Democratic officials.

It was Obama's fourth California fundraiser in three days and was closed to media coverage.

This coming week brings more of the same for the president, including his long-anticipated, first appearance at a campaign rally this election season. At an event Wednesday in Bridgeport, Connecticut, he'll help boost Gov. Dannel Malloy and state Democrats. Malloy is in a tight re-election race in a state Obama won easily in 2012.

Obama has worked hard all year to raise money for Democratic congressional and gubernatorial candidates. But his dismal approval ratings - in the low 40s, according to recent polls - so far have sidelined him from the campaign trail as candidates have avoided appearing with him, especially those from states where Obama lost in past years.

But it has been expected that Obama, unpopular or not, would have to step up his involvement in the final weeks before the Nov. 4 elections, in which control of the Senate will be the night's biggest prize. Democrats are currently in charge of the chamber, but Republicans can regain control by picking up just six seats.

The political party that controls the White House historically loses seats in Congress in the midterm election of the president's second term, history that hardly favors an incumbent nearing the end of six years in office.

Obama has chastised core Democratic constituencies for turning away from politics in nonpresidential election years but also has urged them to snap out of their midterm election slumber and vote next month.

"There's a congenital problem that we have as Democrats, and that is, in nonpresidential elections, in midterm elections, we don't vote. We don't vote," he told about 300 supporters at a Democratic National Committee event at a San Francisco hotel Friday night.

"But the main thing that I need right now is votes. We've got to mobilize. We've got to organize. We've got to knock on doors. We've got to make phone calls," he said. "If young people vote, if women vote, if people of color vote, if people who care about the environment vote, if people who care about LGBT rights vote, that's a majority."

Obama returned to the White House on Saturday after spending the past three days in California, mostly for fundraising. He also raised money this week in New York City and Greenwich, Connecticut, and has similar events in the week ahead.

On Tuesday, he'll help raise money in the Washington area for Democratic House candidates.

On Wednesday, before heading to the Connecticut rally, Obama planned to stop in Union, New Jersey, to help raise money for Democratic Senate candidates.

On Thursday, he travels to New York's Long Island to headline a Democratic National Committee event.