An election that's already considered historic may pass yet another milestone: the first time more Californians cast votes for president by mail than at polling places.

The trend toward voting by mail suits Californians' busy lifestyles, allowing them to work through long, complicated ballots on their own time. But absentee voting could result in delayed results, particularly in tight races, elections experts say.

Californians may know Tuesday whether they helped elect the nation's first African American president or first female vice president. But as county election workers hustle to rip open and verify absentee ballots turned in at the last minute, the outcome of hot-button statewide propositions dealing with abortion and gay marriage, as well as billions of dollars in bonds for hospitals, green energy and schools, could be delayed.

"People want resolution. They don't want to hear that there are a million votes still to be counted," said Mark Baldassare, president and chief executive officer of the Public Policy Institute of California.

The deadline for counties to report pre-election registration is Friday, but preliminary counts already exceed 17 million – higher than the state's previous best of 16.6 million, Nicole Winger, spokeswoman for the secretary of state, said Tuesday.

Statewide, nearly 41 percent of voters asked for mail-in ballots this year. Since a higher percent of absentee voters traditionally cast their ballots, it remains to be seen whether their numbers will overtake votes cast by precinct voters, elections officials said

In an interview with The Bee's Capitol Bureau staff Tuesday, Secretary of State Debra Bowen said the numbers don't worry her.

"Actually, I don't have anything keeping me up at night because I think California is in good shape. … I don't see any meltdowns," she said.

That doesn't mean there aren't localized concerns.

In Sacramento County, the elections office is fielding scores of calls from voters who say they haven't yet received their mail-in ballots.

"I've been trying to get through to the county elections office and can't get through," said Sacramento resident Gina Guarneri. Her college-age children who requested mail-in ballots on Oct. 11 haven't yet received them.

Son Patrick McDougall, 19, is a sophomore at California State University, Chico. Guarnieri's 21-year-old daughter, Jessie McDougall, is a senior at the University of California, Santa Cruz.

"It seems like a lot of hassle," Jessie McDougall said.

Sacramento election officials say a crush of new voters who registered at the last minute is slowing the system. Election workers will begin today to verify absentee ballots that already have been mailed in.

Two local elections officials say they predict mail-in votes will exceed Election Day ballots in their counties.

"We are predicting that 72 percent of all votes cast will come via vote-by-mail," said Jim McCauley, Placer County's registrar of voters.

William Schultz, El Dorado County's chief elections officer, also expected mail-in votes to exceed precinct votes.

"People who request an absentee ballot, nine times out of 10 they are going to vote that ballot," Schultz said.

Yolo County Registrar Freddie Oakley said her employees have no problem handling mail-in ballots. "Our operation is extremely efficient at handling those, so we just love them."

Alice Jarbo, Sacramento County's assistant registrar, said if voters like seeing results election night, absentee voters should drop off ballots or mail them by Friday.

In June, the results of Sacramento's mayoral primary were delayed for days as county staff counted thousands of absentee ballots arriving immediately before the election. Jarbo said in past elections as many as 50,000 ballots were dropped off Election Day.

Before absentee ballots can be counted, they have to be sorted. Voters' signatures must be matched against the signatures they have on file; then the ballots are sent through tabulation machines.

Jarbo said absentee ballots that arrive before Saturday will be processed by Election Day. Their results will be posted after 8 p.m. on Tuesday, making them the first results posted. Once Election Day arrives, staff will turn their attention to precinct votes; remaining absentee ballots will have to wait.

"The more we have in now, the more we can have processed in election night results," Jarbo said.

Opinions differ on the statewide impact of increased mail-in voting. Baldassare of the Public Policy Institute said it is leading to higher participation.

"You are giving busy people who want to be part of the election process – with less time and effort on their part – a chance to be part of the process," he said.

Kim Alexander, president of the California Voter Foundation, said the state should monitor how many mail ballots aren't counted because of voter error, because the registrar's office never receives them or because they arrive after the 8 p.m. Election Day deadline.

Elections officials also have to be vigilant that voters don't vote by mail, then cast a second provisional ballot, she said. "By giving this convenience to voters we've created more work for elections officials," Alexander said.

Call The Bee's Ed Fletcher, (916) 321-1269. The Capitol Bureau's Jim Sanders contributed to this report.