Speculation about who California Gov. Gavin Newsom would choose to fill out the rest of Kamala Harris' U.S. Senate term if she got elected vice president began almost the moment Joe Biden announced her as his running mate.

Now that Harris is vice president-elect, filling her Senate seat is not a matter of if, but who and when. And what are the qualities Newsom should consider as he makes his most important political decision yet as governor? Newsom's considerations include diversity, geography, electability and political compatibility.

Asked on Election Day about the possibility of choosing a successor, Newsom insisted he was not looking forward to it.

"I mean, honestly, I'm not even exaggerating. There's a hundred chores that I'd prefer. I'm not kidding," Newsom joked.

"This is not something that I wish even on my worst enemy, because you create enemies in this process you know, not just friends. And it's a vexing decision. It's a challenging one," Newsom said.

Harris, who was elected to her first Senate term in 2016, would be up for reelection in 2022. Whoever replaces her will get a couple of years in the Senate before running (Newsom has ruled out a special election to fill out the term).

"Diversity is a given," said Newsom's longtime adviser Nathan Ballard. "It's not going to be someone who looks like Gavin," meaning not a straight white male.

The current moment, after George Floyd's death and Harris' focus on rooting racial bias out of the criminal justice system, would seem to rule out likely Senate aspirants such as Rep. Adam Schiff, at least at this time.

For Newsom, there are also other, practical considerations.

"Is it a caretaker, or someone who can turn around a win? Is it someone that's qualified that may not win but would be?" Newsom asked rhetorically.

The shortlist

Kamala Harris is the only Black woman in the U.S. Senate, so you can start there. Would Newsom want to replace her with someone who fits that criteria? In that case, the governor has solid options.

One Bay Area mayor fits the bill, San Francisco's London Breed, who's won high marks for her handling of the coronavirus pandemic. Across the Bay, Mayor Libby Schaaf in Oakland, who is white, also has made a name for herself. Both Democrats have solid relationships with Gov. Newsom and are relatively young.

Rep. Karen Bass from Los Angeles is chair of the Congressional Black Caucus. Bass saw her stock rise during the vice presidential vetting process only to be taken down by stories about her past comments regarding Cuba and Fidel Castro.

But Bass, 67, is well-liked by House Speaker Nancy Pelosi and others in Congress who lobbied Biden's vetting committee to choose her to be his running mate. And as former speaker of the state Assembly, Bass is known as an effective legislator who worked across party lines.

House Minority Leader Kevin McCarthy, R-Bakersfield, who worked with Bass in the legislature, called her "my favorite Democrat," which, considering that's a short list, may not be saying much.

Then there's Rep. Barbara Lee, a longtime friend of Harris and a fellow Oaklander who has represented her city in Congress since 1998. Lee, 74, is also close to the Bernie Sanders wing of the Democratic Party and was the only member of Congress to vote against authorizing the use of force for President George W. Bush before the Iraq War.

Lee also helped bridge the divide between the left-leaning and moderate parts of the party in 2016 after Hillary Clinton won the nomination. That may make her more than acceptable to all parts of the California Democratic Party.

Silicon Valley Rep. Ro Khanna, 44, is also an up and comer after crushing veteran Congressman Mike Honda in 2016. Like Harris, Khanna is Indian American and co-chaired Sanders' national campaign for president this year.

One argument against Breed, Schaaf, Bass and Lee, however, is that none of them has ever waged a statewide campaign in California, which is hardly an easy task given the size of the state and the cost of running.

Secretary of State Alex Padilla has been widely rumored to covet a U.S. Senate seat and is a longtime friend and supporter of Newsom. Padilla chaired Newsom's abortive campaign for governor in 2010 before Jerry Brown jumped in. Padilla was also an early endorser of Newsom while he was running against former Los Angeles Mayor Antonio Villaraigosa and others in 2018.

"Gavin Newsom has just a handful of close friends," Ballard noted. "And Alex is one of them. He's part of that inner circle."

Padilla worked as an intern for Sen. Dianne Feinstein and at age 26 was elected to the Los Angeles City Council. Two years later he became the youngest person ever elected president of the city council.

Padilla, 47, just oversaw a complicated election where, for the first time, every registered voter was sent a vote-by-mail ballot. But the secretary of state was recently caught up in controversy over a $35 million contract for nonpartisan voter outreach that went to a firm linked with Joe Biden. How much the dustup would matter to Newsom is unclear.

But as Ballard tells it, Padilla is near the top of Newsom's list. "He is eminently qualified for the position, and of all the contenders he's the most senatorial," Ballard said, meaning he believes Padilla sounds and looks like a senator.

Ballard noted that Newsom's choice will be on the ballot in 2022 when the governor is up for reelection. "It's almost like having a running mate," he said, adding he wouldn't want to appoint someone who would be a drag on his own campaign. Padilla has run for statewide office twice and won both times.

Another point in Padilla's favor: It's a two-for. If Newsom chooses him, or another statewide officeholder, he would get to name the replacement for that office as well.

Other options

State Sen. Holly Mitchell of Los Angeles would be a dynamic choice to replace Harris. As chair of the state Senate Budget Committee, Mitchell has been a fierce and effective advocate for social justice, working mothers and low-income people. But Mitchell, 56, was just elected to the powerful Los Angeles County Board of Supervisors and would seem unlikely to give that up before she's even sworn in.

Newsom, who said he's been inundated with subtle and not-so-subtle entreaties by would-be appointees, called the decision "vexing" because of all the dynamics involved.

"In this case you've got people that voted for Kamala Harris. And so is it [someone] in her image? Do you sort of extend that narrative?" Newsom wondered aloud.

Newsom, whose recent nomination of a Black, openly gay judge to the California Supreme Court, seems to enjoy making history. In that case, he has several options including:

Others who are either thought to be eyeing this U.S. Senate seat or the one held by 87-year-old Sen. Dianne Feinstein include:

While Newsom eyes these potential picks for political ascension, he has also long eyed higher office. He is widely believed to have seen himself running for president one day, though that option seemingly foreclosed at the moment by the ascension of Harris.

But the former San Francisco mayor has remained quite popular with voters, receiving a 57% approval rating in an October survey from the Public Policy Institute of California. He could decide to run for the U.S. Senate when Feinstein leaves.

In any case, Newsom said on Election Day that he was thrilled for Harris, who has been a kind of "frenemy" or political competitor since he was the city's mayor and she was the city's district attorney.

"I've never seen her more happy, more confident, loose," Newsom said. "She's in her element. And you feel that. You see that. And so I just couldn't be more happy for her. And it's profoundly significant for the state."

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