U.S. Sen. Joe Biden (D-Del.) had little presence in California during the Democratic presidential primary campaign, suggesting he may need to re-introduce himself to voters as Barack Obama's vice presidential running mate.

According to a campaign tracker on The Washington Post's website, Biden made his last stop in California in May 2007, for a town hall meeting and a later speech in San Francisco. Biden dropped out of the race in early 2008, after a series of losses in early primaries.

U.S. Sen. Barack Obama (D-Ill.), who is set to receive the Democratic presidential nomination at the party's convention next week in Denver, tapped Biden as his running mate early Saturday on the basis of his experience, particularly in foreign policy.

In addition to scant appearances in California, Biden did not raise much money here.

According to the Center for Responsive Politics, Biden raised $760,712 during the 2008 presidential cycle. That was less than such candidates as U.S. Sen. Chris Dodd (D-Conn.) and former Sen. Fred Thompson (R-Tenn.), both of whom also dropped out early.

Like many Democratic candidates, Biden raised the bulk of his California cash in two cities: Los Angeles and San Francisco.

According to the center's site, Los Angeles/Long Beach donors gave $456,712, and San Francisco donors gave him $99,350.

Biden raised comparatively little money in many of California's more conservative areas inland, such as Riverside, Fresno and Sacramento.