Who will run for Speier’s seat?

The name mentioned by everyone is Assemblymember Kevin Mullin, who said Tuesday, “I am strongly considering it (running for Congress).” But it may be just a matter of time. Sources say Mullin yesterday began calling around for endorsements.

Mullin would be the favorite. A former South San Francisco councilmember and a second-generation state legislator, he and his wife, Jessica Stanfill Mullin, have twin boys who turn 4 in January.

Mullin probably has the highest name recognition and general goodwill of any Peninsula office holder, after Speier. It does not hurt that Assembly district boundaries dovetail nicely with the congressional district. By the way, the new draft Assembly boundaries cut Mullin out of his district.

Speier did not designate a successor, which is not the same as saying she will not endorse. It seems likely she would endorse Mullin eventually. Mullin is a former aide to Speier, has remained close to the congresswoman and is as close as anyone comes to being her protégé. Full disclosure: I co-host a public affairs TV show with Mullin.

Add in likely endorsements from former state Sen. Jerry Hill, who has said he will not run for Congress, and Congresswoman Anna Eshoo, and Mullin could line up the three biggest names on the Peninsula. The rest of the Peninsula establishment could easily fall in behind him, including his legislative colleagues to the north and south.

Meanwhile, David Canepa, the president of the San Mateo County Board of Supervisors, and re-elected to a second term a year ago, said Wednesday, “We’re in.” He said he would announce formally this weekend. Just 24 hours earlier, Canepa said only that he was “definitely interested.” What changed in one day? A deeper understanding of the district boundaries and a decision not to wait to see who else might run, he said.

On Tuesday, Canepa said, in a comment seemingly intended for Mullin, “This is not a coronation.”

Canepa is not the first Democrat in. That distinction belongs to Burlingame Councilmember Emily Beach, who said Tuesday morning, “I will run for Congress.”

Beach, an Army veteran in her second term on the Burlingame City Council, said she saw Congress as an extension of her long-standing commitment to public service. A vacant congressional seat is “the opportunity of a lifetime. These don’t come up but every 20 years or so,” she said.

Precisely. An open congressional seat is likely to attract an unusually large number of candidates, not just due to pent-up ambition, but because it often is seen as an important office with a low-enough threshold to be winnable by an unlikely candidate.

Expect more candidates — from the left, and from left field. And even a Republican or two, including education consultant and tutor Gus Mattammal from Half Moon Bay, the only formally declared candidate in the race. Still, in a race with a tight timeline that could cost the winner $4 million, conventionality would seem likely to dominate.

And there are a dozen other names, some of whom started by saying they would pass and, as time passed, were rethinking their positions, both publicly and privately.

State Sen. Josh Becker, elected a year ago, said, “I have had a lot of people be really encouraging. I will be talking with people in the next few days.”

Also said to be mulling: Millbrae Councilmember Gina Papan, her sister, San Mateo Councilmember Diane Papan, and Redwood City Councilmember Giselle Hale. Neither Papan would comment on a possible run for Congress. Diane Papan has been preparing openly to run for Mullin’s Assembly seat, which opens up in 2024. A month ago, she formed a Diane Papan for Assembly 2024 campaign committee. It has been thought Gina Papan might run for the Board of Supervisors. Hale said she has made no decision about her future plans for office, although she was presumed to be gearing up for a run for supervisor.

Some or all of these figures could end up running for the Assembly, where Mullin currently has a seat.

So, in the precision of the cliché, anything can happen and the ripples of the Speier announcement have just begun to appear.

Here is what we know for certain: It is the end of an era, and one of the most courageous figures I have ever known is leaving office.

Mark Simon is a veteran journalist, whose career included 15 years as an executive at SamTrans and Caltrain. He can be reached at marksimon@smdailyjournal.com.