It'll be the end of an era in the United States Senate when California's Dianne Feinstein retires at the end of next year. As we've been reporting, she announced yesterday on Twitter that she wouldn't seek re-election and it'll be a hotly contested race, several of her colleagues have already thrown their hat in the ring for the seat. 

For more,  KCBS Radio Anchors Eric Thomas & Margie Shafer are joined by Former San Francisco Mayor Willie Brown and KCBS Insider Phil Matier.