Frank Pallone plans to end his exploration of a 2006 U.S. Senate race soon, according to Democrats close to the Monmouth County Congressman. Pallone isn’t about to give up his House seat for a risky primary against an incumbent United States Senator. The withdrawals of Rush Holt, Rob Andrews and Pallone clears the field for Robert Menendez, who will take his Senate seat this week. Pallone, a Congressman since 1988, is not likely to have another shot at statewide office. He passed up the Democratic nomination for an open Senate seat in 2002 and backed off runs for the Senate in 2000 and for Governor in 2001; Democrats probably won’t take his statewide aspirations if there is another opportunity in the future.