SANTA BARBARA, Calif. — Gov. Gavin Newsom (D) selected on Tuesday his longtime political ally and current California secretary of state Alex Padilla to fill the U.S. Senate seat of Vice President-elect Kamala D. Harris when she steps down next month.

The choice makes Padilla the first Latino to represent California in the Senate in the state’s 170-year history.

“The son of Mexican immigrants — a cook and house cleaner — Alex Padilla worked his way from humble beginnings to the halls of MIT, the Los Angeles City Council and the State Senate, and has become a national defender of voting rights as California’s Secretary of State,” Newsom said in a statement. “Now, he will serve in the halls of our nation’s Capitol.”

Padilla filled a number of New­som’s criteria for the choice, including recent political success in statewide races. He will have to defend the seat in two years, a quick turnaround in a vast, expensive state in which to campaign. In 2018, Padilla won more votes than Newsom on the ballot.

Newsom was also under pressure from Latino organizations to choose a member of the state’s largest ethnic group. Latinos are a powerful voting bloc in the state, even if not always as liberal as the rest of the Democratic Party here.

In addition, Latinos have suffered disproportionately this year from the coronavirus pandemic. Accounting for about 40 percent of the population, Latinos have made up 60 percent of the state’s coronavirus cases, many of them essential workers in the service economy.

“From those struggling to make ends meet to the small businesses fighting to keep their doors open to the health-care workers looking for relief, please know that I am going to the Senate to fight for you,” Padilla said in a statement. “We will get through this pandemic together and rebuild our economy in a way that doesn’t leave working families behind.”

The selection represents the first — and highest-profile — of the political dominoes now falling here in the aftermath of the Biden-Harris victory. Harris is expected to resign her seat before she is sworn in as vice president on Jan. 20.

Many around Newsom had predicted a longer selection process to fill the seat given the time-consuming diplomacy involved in the decision, which raised in relief the array of ethnic, geographic, equal rights and economic lobbies at play in California politics. Suddenly, Newsom had two state elected offices — the secretary of state, which oversees elections, and the attorney general — to fill by appointment.

He acted quickly, though. Hours after naming Padilla to the Senate seat, Newsom nominated State Assembly member Shirley Weber (D), a San Diego State University professor and a powerful voice in the legislature for criminal justice reform and equal rights legislation, as secretary of state.

Weber, chairwoman of the California Legislative Black Caucus, will be the first African American in state history to hold the post. Weber’s nomination must be confirmed by the state Senate and the Assembly within 90 days.

Newsom, whose approval ratings remain high despite the criticism he has received for his handling of the pandemic, is a politician who has always been drawn to “firsts.” As mayor of San Francisco, Newsom in 2004 began marrying same-sex couples in the city long before the Supreme Court recognized those unions as legal.

In selecting Padilla, Newsom has achieved another first, while disappointing those who had hoped the seat would go to an African American woman to fill the demographic opening left by Harris. Padilla will increase the number of Latinos serving in the Senate to six after Sen.-elect Ben Ray Luján (D-N.M.) is sworn in Jan. 3. There will be no Black women in the chamber.

Padilla has been one of the governor’s most loyal political allies, endorsing Newsom in his eventually aborted run for governor against Jerry Brown (D) in the 2010 election. He is also from the Los Angeles area, bringing slightly more geographic diversity to leadership in a state where many of the most powerful positions are filled by Bay Area politicians.

For weeks a leading candidate for the post, Padilla emerged as the clear front-runner this month after President-elect Joe Biden chose Xavier Becerra, the state’s attorney general, to serve as secretary of health and human services. Becerra and Long Beach Mayor Robert Garcia (D) were the two other Latinos seen as the most likely picks for the Senate seat.

In a statement, the Congressional Hispanic Caucus thanked Newsom “for meeting this moment and helping to write the next chapter of California and American history.”

“As our nation confronts an ongoing pandemic and an economic crisis, both of which have disproportionately harmed Latino families, it is more important than ever for Latino perspectives to not only be heard, but to have the power to shape policy at the highest levels,” the caucus said in the statement.

Padilla, 47, grew up in the San Fernando Valley neighborhood of Pacoima. His father, Santos, and mother, Lupe, immigrated to the United States separately from Mexico and met in a downtown Los Angeles dance hall. In past interviews, Padilla has said his parents may have immigrated without visas, then returned to Mexico to apply for U.S. residency papers that were granted. Santos worked as a short-order cook and Lupe as a maid in several households.

Padilla graduated from MIT with a degree in mechanical engineering, later serving on the school’s board of trustees.

At age 26, he was elected as the youngest member of the Los Angeles City Council, representing the area where he grew up in the city’s northeast. Two years later he was elected by the council as its president, the youngest person to hold the position and the first Latino to do so. He then served two terms in the state Senate.

As secretary of state, Padilla oversaw an election with more Californians casting ballots than ever before. His choice of a consulting firm at which Biden campaign adviser Anita Dunn is a partner, though, proved controversial and potentially expensive for the state.

Padilla selected SKDKnickerbocker— the “D” stands for Dunn — to conduct a voter education campaign explaining the changes in voting rules brought by the pandemic. The choice was criticized by state Republicans and others for the apparent conflict of interest it represented. The state comptroller also notified Padilla’s office that it didn’t have the authority to spend the money on the $34 million effort. The balance is in limbo.

Even before the presidential election, though, Padilla had become the choice for several Latino groups. The D.C.-based Latino Victory Fund started the campaign with a “Pick Padilla” lobbying effort weeks before the Biden-
Harris ticket won the election.

One weakness in Padilla’s résumé for the job is his lack of Washington experience. He enhanced his profile among other Latino leaders and in the capital, though, as the former head of the National Association of Latino Elected and Appointed Officials.

In a statement, Sen. Dianne Feinstein (D-Calif.) called Padilla an “excellent” choice, commending his experience and knowledge of state issues.

“Alex has a long record of public service at all levels of government,” Feinstein said. “Alex is someone who understands the many challenges that Californians are facing, and I believe he is very well-suited to fight for them for years to come.”

But Padilla’s selection is likely to upset a number of groups that lobbied for an African American woman to replace Harris, who was only the second Black woman to serve in the U.S. Senate. Rep. Karen Bass (D), who is from the Los Angeles area, and Rep. Barbara Lee (D) of Oakland were championed as strong candidates to fill the post. Both have years of Washington experience, but neither has won a statewide race.

“Our state gains yet another champion following a distinguished line of individuals who have shattered glass ceilings and hurdled obstacles in their way,” Bass said of Padilla in a statement. “After then-Senator Harris’s historic election in 2016 as the first woman of color to represent California, we now have another historic barrier shattered.”

Dave Weigel and Mike DeBonis contributed to this report.