The Eye

Tauscher was offered the position of undersecretary of State for arms control and international security and is expected to resign her seat following confirmation by the Senate.

Buchanan's entry to the race occurred one day after California's lieutenant governor, Democrat John Garamendi, announced he would exit the 2010 race for governor and instead campaign for the 10th District.

Garamendi's entry shook up the early candidate field that had begun to form. Democratic state Sen. Mark DeSaulnier appeared to be an early favorite. DeSaulnier received endorsements from Tauscher as well as Democratic Rep. George Miller, whose 7th District is adjacent to the East Bay suburban 10th District.

Buchanan is the first major female candidate to announce her intention to run for the seat.

The district leans Democratic, but district voters have favored centrists such as Tauscher. A CQ Politics analysis of presidential votes by congressional district shows that President Obama outran Republican John McCain by a 32 percentage-point margin in the 10th.

Democrat Adriel Hampton, municipal investigator for the San Francisco City Attorney's Office, is campaigning for the seat and news reports suggest Anthony Woods, an Army veteran of the Iraq war, is considering a campaign.