Not exactly polarization

Democrat Frank Lautenberg, New Jersey's 200-year old senior senator, may be challenged by Rep. Rob Andrews (D-Haddon Heights) in this year's senate primary. The weird thing is, according to Poole and Rosenthal's calculations, Andrews is actually more moderate than Lautenberg, which makes one wonder what the basis for this challenge would be. Andrews' most recent DW-NOMINATE score is -.438; Lautenberg's is -.573. (Yes, different chambers, I know, but still...)

According to Andrews' people:

Over the last few days, Congressman Andrews has been approached by many leaders of the Democratic Party who have urged him to step forward and run for the Senate because they think that 2008 is a year where voters are seeking a change in government.

Pretty vague. I wonder who these "leaders of the Democratic Party" are, considering that Gov. Corzine, Sen. Menendez, and the rest of the House Dems from NJ are already backing Lautenberg.