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."
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.
In trying to compete in New Jersey, Hugin, like Menendez, has painted a picture of humble roots in the state. He grew up in Union City, New Jersey, and said he became the first person in his family to attend college when he went to Princeton University.
Menendez, a son of Cuban immigrants, also highlights his upbringing in Union City. His Senate website says he attended public schools, then went to both college and law school in the state at St. Peter's College and Rutgers University, respectively.
In trying to win the blue-state seat, Hugin has aimed to show he can differ from President Donald Trump or Senate GOP leaders and work with Democrats on key issue areas. Hugin will likely continue to spend his own money heavily in order to spread that message, telling CNBC he will shell out as much as he feels is necessary to reach voters.
His campaign says he could spend a significant amount more of his own wealth during the general election campaign, further inundating voters with criticism of Menendez. Hugin has a lot to spend: tax returns show he and his wife earned nearly $34 million in 2015 and 2016 alone, according to Politico.
It is unclear whether national GOP groups will support Hugin, given his personal wealth and the battleground races elsewhere. The Senate Leadership Fund PAC, which is linked to Senate Majority Leader Mitch McConnell, would not say whether it planned to put money into the race but added that is "generally supportive" of Hugin.
Menendez is also no slouch in raising campaign funds: he had nearly $5.6 million in cash on hand as of mid-May.
Last week, Hugin told CNBC that he sees health care as "an area where [he] can be a very positive force for ensuring that we have the kind of substantive dialogue on a bipartisan basis to deal with these issues."
He called Trump's drug pricing plan, which aims to create more competition, improve price negotiations and targets companies such as Celgene, an "important first step." He pushed for the "same kind of comprehensive assessment about outcomes and value and affordability of our entire health care system."
Hugin has wants to maintain the "level of resources" allotted to Medicaid, the federal and state insurance program for low-income Americans, while giving individual states more room for innovation within the program. He has also called for "reasonable" out-of-pocket spending caps for patients with diseases such as cancer, arthritis and HIV.
Menendez as senator has opposed Republican efforts to repeal and replace the Affordable Care Act, which were expected to lead to more people losing insurance, higher average individual premiums and less federal money available to Medicaid than previously allocated. He has pushed for bipartisan action to rein in premium increases, which were partly brought on by the Trump administration's actions.
Menendez's campaign highlighted the senator's priorities ahead of the primary, saying he wants to make sure that "every New Jerseyan has access to affordable, quality health care," prevent "senseless gun violence" and grow the U.S. economy in a way that lifts "everyone, not just the wealthy."
Hugin also says he wants to work with Democrats on immigration. He echoed other centrist Republicans in calling for comprehensive immigration reform that includes a pathway to citizenship for young immigrants brought to the U.S. illegally as children.
Hundreds of thousands of those immigrants were protected from deportation by the Deferred Action for Childhood Arrivals program, which Trump tried to end before the decision got held up by courts. Currently, moderate Republicans and Democrats in the House are trying to force a vote on immigration packages that would not include Trump's proposals to limit legal immigration.
"I believe that safe secure cities are important, securing the borders, and we should provide a path to citizenship for the people here building a constructive, productive life — whether that means they're going to school and looking to build a life here in the United States, or they're working and paying taxes and living a constructive life," Hugin said.
Menendez is part of a bipartisan group of senators seeking legal protections for so-called Dreamers without the tight restrictions on legal immigration supported by Trump. As of last year, New Jersey had the ninth-highest number of individuals protected from deportation by DACA among states, according to U.S. Citizenship and Immigration Services.
While he supports the corporate and individual tax reductions in the GOP tax law passed in December, Hugin criticized the $10,000 cap set on state and local deductions popular in his high-tax state. Numerous GOP House members from New Jersey and New York opposed the legislation because of the provision. Hugin wants to raise the cap, potentially to $15,000, to reduce possible negative effects on the New Jersey economy.
Menendez opposed the tax plan, saying it helped corporations too much at the expense of working-class taxpayers. He also heavily criticized limits on state and local tax deductions, calling them earlier this year "a way to exact political revenue against so-called blue states."
— CNBC's Brian Schwartz contributed reporting to this article