There was a bit of movement today in the traffic jam facing the Democrats over the 20th Senate district in the Valley. Incumbent Richard Alarcon is vacating to run for the state Assembly, apparently on a quest to become Speaker. Everyone assumes the race to succeed him will pit City Council president Alex Padilla against the current Assembly member for the area, Cindy Montañez, unless she is persuaded to seek another office (perhaps even the L.A. City Council, if she moves into the city's borders to meet the residency rules.) Anyway, today U.S. Sen. Dianne Feinstein endorsed Padilla. "Alex is a proven leader with a record of getting things done for the San Fernando Valley," Feinstein says in the press release. (* Just to note: Montañez's endorsements for the Senate thus far include Alarcon, Speaker Fabian Nuñez, and City Controller Laura Chick.)