The congressman had been challenged by Hoboken Mayor Ravi Bhalla, who waged a campaign largely based around the elder Menendez. Though the congressman has not been linked to his father's alleged misdeeds, he has defended him amid the charges, and he pointedly declined to offer an opinion on his father's looming independent Senate bid during an interview with Business Insider in April.

"I don't have the capacity to think through, well, what if, what if, what if," Menendez said at the time. "There's a lot that I have to deal with right now."

Bhalla would have made history as just the second Sikh American ever elected to Congress, and the first to wear a turban.

The primary was also a key test for how candidates will run without the so-called "county line" system, which has enabled machine politics to persist for decades in New Jersey. It's essentially a ballot design trick that has allowed party organizations to hand-pick candidates in state elections for decades.

Following a lawsuit from Rep. Andy Kim amid his short-lived primary campaign against First Lady Tammy Murphy, a federal judge struck down the system for the June primary, and it could be invalidated forever. Kim officially became the Democratic nominee for Senate in Tuesday.

That system enabled the coronation of Menendez by party leaders in 2022, despite holding no elected office before.

During one recent debate, Bhalla alleged that he was essentially pressured into endorsing the younger Menendez that year, and that Sen. Menendez was on speakerphone with his son during the call.