On March 16, the very last day for candidates to file for Congress in California’s June primary, Ron Unz filed for U.S. Senate. See this story. There are now three well-known California Republicans running for U.S. Senate: Unz, past state Republican Party chair Duf Sundheim, and past state Republican Party chair Tom Del Beccaro.

Because there are only two well-known Democrats running in the same top-two primary, the entry of Unz makes it even more likely that the only two candidates on the November ballot will be those two Democrats, Kamala Harris and Loretta Sanchez.

Unz received 34% of the vote when he ran for Governor in the Republican primary of 1994, against the incumbent, Governor Pete Wilson. Unz is best known for sponsoring a winning initiative that limited bilingual education in California public schools. Here is the wikipedia article about Unz.