Will an endorsement a day make a primary challenge go away? That's certainly what New York Sen. Kirsten Gillibrand is hoping with the daily drip-drip-drip of 2010 endorsements her campaign has announced.

Wednesday the endorser was former New York City Mayor Ed Koch (1978-89), a popular figure downstate. Koch, like Gillibrand, built a record as a centrist Democrat, even going so far as to endorse several Republican statewide candidates, as well as Republican President George W. Bush in 2004. Koch endorsed Democrats Hillary Rodham Clinton and then Barack Obama in the 2008 presidential race.

Of Gillibrand, Koch said in a statement that he was impressed with her "ability to understand the concerns of all New York families and to form a legislative agenda to address those concerns."

Reps. Nydia M. Velazquez and Edolphus Towns endorsed appointed Sen. Kirsten Gillibrand's bid for the Democratic Party's 2010 Senate nomination in New York, narrowing the field of potential endorsements for a possible rival.

In particular, Velazquez's endorsement is important because Gillibrand has been criticized by Latino officials for her voting record on immigration issues when she represented a swing district in upstate New York in the House of Representatives.

Velazquez is the only Hispanic woman ever to chair a full committee in the House. Towns, who was first elected in 1982, represents a black-majority district in Brooklyn.