Senate Majority Leader Harry Reid is the latest member of the Democratic Party establishment to get behind appointed New York Sen. Kirsten Gillibrand‘s 2010 campaign.

Reid, a Nevada Democrat, joined a growing list of Gillibrand backers, including former Democratic National Committee Chairman Howard Dean, who announced his support on Thursday.

Gillibrand has been hustling to line up support from congressional colleagues and Democratic support groups in advance of an expected primary challenge by nine-term Rep. Carolyn B. Maloney. Aides to Maloney have said that she will announce in late July that she is a candidate for the 2010 special election.