Democratic legislative leaders declared Wednesday that they had captured a supermajority of each house, the first time in more than 100 years that the party has wielded such power.
With all precincts counted, Democrats led in enough races to clear that two-thirds threshold, which would allow them to pass tax increases without needing GOP votes. Such a supermajority would also allow Democrats voting as a bloc to place constitutional amendments on the ballot or override vetoes of Gov. Jerry Brown.
Assembly Republicans held out hope that they could reverse the trend in two races as ballot-counting continued.
Analysts said it was nonetheless clear that Democrats benefited Tuesday night from strong turnout by President Barack Obama's supporters, youths concerned about rising college costs, and Californians drawn to cast ballots on proposals to raise taxes and stop funds deducted from union paychecks from being used in political campaigns.
They entered Election Day needing two additional seats in the Assembly and two in the Senate to gain a two-thirds majority not wielded by their party since 1883.
Senate President Pro Tem Darrell Steinberg and Assembly Speaker John A. Pérez talked Wednesday as if it were a fait accompli.
"I promise that we will exercise this new power with strength, but also with humility and reason," Steinberg said. "I certainly don't intend to suggest to my colleagues that the first thing we do with our new power is to go out and seek to raise more taxes."
Senate GOP leader Bob Huff, who conceded that Democrats appeared to have secured a supermajority, said Senate Republicans "clearly don't see this as a mandate."
"It means that even the governor, who normally can be a moderating force when laws run amok even his vetoes could be overridden," Huff said. "So it's going to be an interesting dynamic.' "
Jon Coupal, president of the Howard Jarvis Taxpayers Association, said it would create a dangerous, one-party rule and leave California "very close to becoming a banana republic."
"They say that absolute power corrupts absolutely," Coupal said. "I think we're in significant danger of that in California."
Brown said holding the voters' trust is no easy thing, and that he plans to hold a careful line on spending.
"We have to make sure over the next few years that we pay our bills, we invest in the right programs, but we don't go on any spending binges," he said.
The Democratic governor said he will be guided by a biblical reference to years of plenty being followed by seven years of famine.
"We need the prudence of Joseph going forward over the next seven years, and I intend to make sure that that's the story we look to for guidance," he said.
Even with a supermajority, Democrats might not vote unanimously on taxes or other controversial legislation, given the growing number of moderate and business-friendly members.
Pérez said Democrats will use their dominant numbers to continue pushing for priorities of the past few years, including restoring budget stability and encouraging job creation.
He downplayed the notion of trying to extract more tax revenue: "We're not looking to figure out new ways to do things that we've said we're not going to do."
Pérez said he would continue pushing for middle-class college scholarships, a priority for him last year that died in the Senate.
Steinberg talked of using the supermajority to reinvest in public schools and colleges, restore adult dental care for the poor, and alter the initiative process in a way that makes it harder for millionaires to impose their will by spending vast sums qualifying a measure for the ballot.
The Senate leader said he might be willing to consider overhauling the state's income tax structure to lower rates but broaden the base, and to consider a constitutional amendment laying the groundwork for same-sex marriage.
Although Pérez said the outcome already is clear based on votes remaining to be tallied, Assembly GOP leader Connie Conway wasn't ready to concede two of her races.
In Orange County's 65th District, Democrat Sharon Quirk-Silva leads incumbent Republican Assemblyman Chris Norby by one percentage point. In the 32nd District, Democrat Rudy Salas is edging Pedro Rios by less than one-half of a percentage point.
In Sacramento County, Democrat Ken Cooley leads Peter Tateishi by nearly 5,000 votes in Assembly District 8. Tateishi said he would see if trends continue through early counting of outstanding mail ballots before considering a concession.
Pérez expects to control 54 of the Assembly's 80 seats, a net gain of two.
In the Senate, Democrats captured three new seats: Fran Pavley beat Todd Zink in District 27, Los Angeles and Ventura counties; Richard Roth beat Jeff Miller in District 31, Riverside County; and Hannah-Beth Jackson beat Mike Stoker in District 19, Santa Barbara and Ventura counties.
Steinberg had not given up Wednesday on one other Senate contest. Republican Bill Berryhill led Democrat Cathleen Galgiani by two percentage points in the 5th Senate District of San Joaquin, Stanislaus and a sliver of Sacramento counties.