Hugin has already put millions of his own dollars into his campaign to spread a centrist message and attack Menendez for corruption accusations.

Menendez's lackluster showing in beating a largely unknown primary challenger shows he may need to work had to win in the blue state.

Bob Hugin, a Republican candidate running in New Jersey primary election for U.S. Senate, gestures while exiting a polling booth after casting his vote in the New Jersey Primary Election, Tuesday, June 5, 2018, at the Lincoln-Hubbard School in Summit, N.J. Julio Cortez | AP

Senate primaries in New Jersey on Tuesday set up what could become a competitive — and nasty — race for scandal-plagued Democratic Sen. Bob Menendez's seat. Republican and former Celgene CEO Bob Hugin — who has already put $7.5 million of his own into his campaign to spread a centrist message — easily won his party's primary. On the Democratic side, Menendez garnered about 62 percent of the vote in beating largely unknown challenger Lisa McCormick, a showing considered disappointing for an incumbent. The outcomes show Menendez, 64, may have to labor to keep a blue-state seat that, in most years, would be relatively easy for Democrats to hold. Democrats cannot afford to lose the race as the party's incumbents and independents who caucus with them defend 26 seats in November. Many of those races will take place in states with a more dominant Republican presence than New Jersey. Hugin, employing his vast wealth to blanket airwaves with television ads, has cast himself as an independent voice who may not fall in line with Republican leaders on issues such as health care, immigration and abortion. He and national Republicans have repeatedly hammered Menendez for charges that he took gifts from wealthy Florida eye doctor Salomon Melgen in exchange for favors. The Justice Department dropped charges against Menendez, but bipartisan colleagues admonished him earlier this year for his conduct. Republicans jumped on Menendez's Tuesday primary performance. In a statement following the primaries, National Republican Senatorial Committee executive director Chris Hansen said that "after years of nothing but embarrassment and scandal from Menendez, New Jerseyans agree it's time for a fresh voice in the U.S. Senate."

Sen. Robert Menendez, a Democratic senator from New Jersey Peter Foley | Bloomberg | Getty Images

In declaring victory in his primary Tuesday night, the 63-year-old Hugin took a dig at Menendez, saying he wants to give "New Jersey a senator it can be proud of." The Marine veteran also pledged to cooperate with Democrats if he wins the Senate seat. "In the Marines, it's not about Democrats or Republicans, it's about working together. Frankly, that's what we need more of in Congress, and that's the kind of senator I will be for New Jersey — an independent voice who always puts our state and our people first. No exceptions," Hugin said. "I am pro-choice, pro-marriage equality, and I strongly support equal pay for equal work. I believe we — as a party and as a country — need to fix our immigration system in a comprehensive and compassionate way." The Menendez campaign did not respond to a request for comment on Hugin's rhetoric or the senator's primary performance. Even before the primary, his campaign started hitting Hugin for massive increases in the price of a cancer drug while the GOP candidate was at Celgene. The Democrat's operation also noted that the Trump administration this year singled out Celgene as one of the companies working to hinder the development of cheaper generic alternatives to its drugs. Hugin has gotten a boost from the corruption accusations against Menendez. But in trying to win over the independent or crossover voters needed to prevail in blue New Jersey, he likely needs to run more than an anti-Menendez campaign.

How Hugin and Menendez stack up