On Monday, a full page ad addressed to Newsom ran in the San Francisco Chronicle urging him to appoint a woman of color. The open letter -- signed by roughly 150 women from the "Election Women Bay Area" and "LA Women's Collective" groups -- points out that with the departure of Harris there will be only three women of color in the entire Senate.
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"Women of color are the core drivers of electoral progress in our country, and their voices should be heard in the nation's highest governing body," the letter says.
The open letter only adds to the public pressure Newsom is already facing as he makes his senate pick. Former San Francisco Mayor Willie Brown is openly urging his former mentee to not only commit to a woman of color -- but to a Black woman. He says there are several good options, including Congresswomen Barbara Lee, Maxine Waters and Karen Bass, and even San Francisco Mayor London Breed.
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"We've only, in the history of this nation, had two Black women in the U.S. Senate: Carol Moseley Braun and Kamala Harris," Brown told ABC7 News. "And to fill that with someone other than a Black woman, I think, would be inconsistent with really good judgement."
Of course, not everyone agrees. On Monday morning, Latino leaders from across the state came together to urge Newsom to appoint California's first-ever Latino Senator. They said it's time the state's 15 million Latinos - making up roughly 40% of California's population - are better represented.
"Our hardworking agricultural and service workers have helped keep this country afloat," San Jose councilmember Magdalena Carrasco said. "They deserve a leader who can speak directly to their needs. They deserve a voice on the Senate floor."
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Asked about this push for a Latino, former Mayor Brown stood by his belief that Harris' seat should go to a Black woman.
"Why would you replace the only Black woman with somebody other than a Black person? Racial minorities should know they should not try to fill each other's vacancies," Brown said. "If it was a Latino, I would be doing exactly that, I would be supporting the Latino candidate. But in this case it's a Black woman."
Secretary of State Alex Padilla, a Latino, is rumored to be a frontrunner. But at Newsom's press briefing Monday, he gave few hints on his choice or timeline, except to say it would be made before the Inauguration on Jan. 20th.
"That determination has not yet been made, but progress has been made in terms of getting closer to that determination," Newsom said.
Until then, the lobbying continues.
"It's like a three level game of chess: You have Gavin Newsom and his personal political interests, then you have the states' various groups moving in. But in this case, and this is rather unique, you have national attention as well," San Francisco Chronicle columnist and ABC7 News contributor Phil Matier said. "Everybody has a little chip in this mosaic and it's up to Gavin to figure out how he wants to play."