By Ian Bush
PHILADELPHIA (CBS) -- The Senate's oldest member says he won't run for re-election next year. Frank Lautenberg faced a threat from a popular figure in his own party.
Those who don't know much about Cory Booker's ideology at least know he's been called the "hero" mayor of Newark.
"Booker is probably the most popular Democratic politician in New Jersey at this point," says La Salle University provost and New Jersey politics expert Joe Marbach.
That played into Lautenberg's decision to call it a career.
"Lautenberg knew that if he was going to defend his seat, he was going to have to raise a lot of money and wage a really vigorous campaign against Cory Booker, who's all over the media, whether it's social media or broadcast media."
Not that Lautenberg was ready to go; the 89-year-old may have seen Booker's early declaration to run as giving the old man the heave-ho before his time.
"A number of members of the Congressional delegation -- Rep. Frank Pallone comes to mind -- have also expressed an interest in that seat."
So even without Lautenberg, Marbach says, it could still be a hot race even before the winner has to face a Republican.
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