WASHINGTON (AP) — California Sen. Kamala Harris offered a deeply personal attack Thursday on former Vice President Joe Biden, reminding a national television audience that he opposed public school busing in the 1970s. She said she was one of the students being bused then, and decried Biden as long being on the wrong side of the issue. Biden was left angry and flustered. The extraordinary moment could shake up the Democratic presidential primary _ possibly denting Biden’s early lead over the rest of the field.