Steve Cooley had claimed victory on election night, only to discover the next morning that he was behind. The lead has gone back and forth since, but Harris has held an advantage for more than a week. (Anne Cusack, Los Angeles Times / October 13, 2010)

With the stack of ballots left to count sharply diminished, San Francisco Dist. Atty. Kamala Harris continued to hold a steady lead Tuesday in the race for attorney general, making victory over Los Angeles County Dist. Atty. Steve Cooley all but assured.

Harris, the Democrat, led the Republican nominee by nearly 53,000 votes - 4,385,438 to 4,332,596 - according to a Times review of updated vote tallies in all 58 counties. Although the gap remains narrow in one of the closest statewide races in California history, the chance for Cooley to pick up enough votes to make up the difference appears increasingly remote.

The secretary of state reported late Tuesday that there were 154,806 ballots left uncounted statewide. To win, Cooley would need more than two-thirds of those to overtake the Democratic nominee. So far, the gap between the candidates has been less than a single percentage point. Moreover, about two-thirds of the remaining votes are in counties that Harris carried, including Contra Costa, Monterey and Sonoma.

"It's over," said Bob Mulholland, a longtime Democratic Party strategist. "Cooley, if he was professional enough, would call Harris before she cuts her turkey on Thursday."

But Allan Hoffenblum, a former GOP consultant, urged caution until the last votes are tallied. He said the winner may not be formally known for some time if one of the candidates seeks a recount, an expensive proposition that the candidate would have to pay for.

"I think it's one of these cases where it's not over until it's over," said Hoffenblum, who publishes the nonpartisan California Target Book, which analyzes political races.

Neither campaign released a statement Tuesday. Cooley had claimed victory on election night, only to discover the next morning that he was behind. The lead has gone back and forth since, but Harris has held an advantage for more than a week.

County registrars in California have 28 days after an election to tabulate all the votes. When election day - Nov. 2 - ended, more than 2 million ballots remained to be counted, including mail-in ballots that arrived that day.

At this point, most of the remaining votes are provisional ballots, which are given to voters when polling places do not have a record of their registration, often because a voter has moved since registering.

Before a provisional ballot can be counted, election officials must verify that the voter was registered and that the signature on the ballot matches voter registration records. Provisional ballots must also be checked to make sure that votes were not cast in local elections outside the jurisdiction in which the voter lived. About 80% to 85% of provisional ballots are usually deemed valid, according to the Los Angeles County registrar-recorder/city clerk's office.