Sen. Frank Lautenberg (D-NJ) once again has a serious challenge for his seat -- though this one is from a fellow Democrat. Rep. Robert Andrews announced yesterday he will be running for the seat Lautenberg has held since 2002. Lautenberg previously held New Jersey's other Senate seat from 1982 through 2000.

Andrews has represented New Jersey's 1st District since 1990, never winning less than 67% of the vote after his first general election. The congressman has previously sought higher office -- he lost the 1997 Democratic primary for governor, and later indicated interest in replacing Gov. James McGreevy and Senators Jon Corzine and Bob Torricelli after all three resigned, though his efforts were thwarted in each occasion.

Lautenberg, who turned 84 this year, avoided a serious challenge from real estate developer Anne Estabrook, a Republican whose moderate politics and ability to self-finance a campaign made her candidacy especially potent. Estabrook withdrew from the race in early March after suffering a mild stroke.