Democratic strategist Mike Semler — who has advised Senator Dianne Feinstein and who has taught public policy at Cal State University Sacramento — this weekend sent out an emergency email alert seeking support for an effort to back a ballot measure to save the mural. He said the effort, dubbed the Coalition to Protect Public Art, aims to solicit funds to initiate a ballot measure designed to protect this art, “and perhaps other New Deal art in San Francisco’’ which may also be targeted.

With their move, the school board is “saying we’re all going to jump in this ship together and paddle left,’’ says Semler. “This is Nancy Pelosi’s district. This is where Kamala Harris is from. Clearly, this is not San Francisco values.”

The presidential campaign of Senator Harris, and the Speaker‘s press office, did not respond to requests for comment Sunday.

The school board vote in June has set off a growing chorus of protest from Democrats — many in the political establishment — who say that the move to erase history is not only expensive folly, but could hand Trump fodder to suggest Democrats are out of touch with the mainstream headed toward 2020.