Washington ? Federal Reserve Chairman Ben Bernanke encountered new Senate opposition Friday for another four-year term as the White House worked aggressively to keep his support from eroding further.

President Barack Obama’s chief of staff, Rahm Emanuel, and Treasury Secretary Timothy Geithner were on the phone throughout the day to key senators to shore up votes, said two senior administration officials, speaking on condition of anonymity to more freely discuss behind-the-scenes activity.

On Friday, three Democrats — Sens. Russ Feingold of Wisconsin, Barbara Boxer of California and Jeff Merkley of Oregon — announced they would vote against Bernanke’s confirmation. A fourth Democrat — Sen. Byron Dorgan of North Dakota — announced his opposition Thursday.