SACRAMENTO, Calif. (AP) — Stockton Mayor Michael Tubbs, who skyrocketed to national attention as one of the youngest mayors of a big city in the country, says he is “100%” confident he will win reelection despite early returns in San Joaquin County that show him trailing his Republican challenger.

Tubbs, 30, who was raised by a single mother after his father was imprisoned for most of his life, graduated from Stanford University and interned in the Obama White House before returning to Stockton to run for city council in 2012, when he was just 22. Oprah Winfrey endorsed him in 2012, and then-President Barack Obama backed his run for mayor in 2016.

But after getting more than 70% of the vote in 2016 to become Stockton's first Black mayor, Tubbs is still trailing Republican Kevin Lincoln by about 2,000 votes after three days of counting.

The numbers have surprised California Democrats, who have viewed Tubbs as a potential candidate for statewide office. And it's raised questions about the political effect of some of Tubbs' most ambitious experiments, including privately funded programs that pay small groups of lower-income or disadvantaged people between $500 and $1,000 a month in an effort to combat poverty and violent crime.

In an interview with The Associated Press on Friday, Tubbs insisted he is behind not because he lacks support, but because of the way San Joaquin County Registrar Melinda Dubroff is counting the votes. Through Thursday, the registrar's office has counted only ballots cast in-person on Election Day or mail-in ballots received prior to Oct. 30, he said.

Statewide, registered Democrats were more likely to vote by mail while registered Republicans were more likely to vote in person. Tubbs says there are still about 44,000 vote-by-mail ballots to be counted and he expects the vast majority to be for him.

“The current vote count reflects an overabundance of conservative voters, which will be radically different once all the votes are counted,” Tubbs said. “The frustration is, it's taking the registrar a lot of time to count the ballots. I think in that window of time there's anxiety building up where people are trying to Monday morning quarterback.”

A San Joaquin County spokeswoman could not verify how many ballots were still left to count in Stockton, saying the whole county has more than 125,000 left.

But Lee Neves, a Stockton-based political consultant, said lots of Democratic votes came in early.

“He really should have been in the lead,” Neves said of Tubbs. “It's a toss-up.”

Lincoln, Tubbs’ opponent, said he's “feeling pretty good” about his chances. The 40-year-old pastor of LifeSong Church, who was born and raised in Stockton, said Tubbs’ pursuit of national notoriety has caused him to neglect his duties in Stockton, marginalizing many residents and contributing to “a huge increase of distrust in our city.”

“The trend has been going in the same direction, we’ve continually increased our lead,” he said. “Our hope is that through the weekend this trend will continue.”

Lincoln, the son of a Mexican mother and an African American father, also left Stockton — to become a Marine. He was eventually assigned to Marine One, the call sign for the aircraft that carries the president, later worked for a private security company in Silicon Valley, and then returned to Stockton to become executive pastor for LifeSong Church.

A local website, 209 Times, has also weighed in on the race. Activist Motecuzoma Sanchez, who unsuccessfully ran for mayor in the March primary and co-runs the site, said he is devoted to “exposing Michael Tubbs and who he really was.”

“(Tubbs) was spending so much time outside of the city promoting himself and his political branding, that he was neglecting the fundamental duties of why he was elected,” Sanchez said.

Michael Fitzgerald, a retired columnist for The Record newspaper in Stockton, said the group has “published a nonstop narrative of lies and distortions” about Tubbs that have been difficult to counter.

Tubbs said 209 Times did not have the power “to change the election,” adding he still has “a very strong base."

“If I'm wrong, I'm happy to come back and have a conversation about things,” he said.