WASHINGTON -- U.S. Sen. Robert Menendez is "leading a lavish lifestyle courtesy of corruption." Former Celgene Corp. executive Bob Hugin is a "greedy drug company CEO."

Those comments from their opponents' camps come even before they win their parties' nominations. And their underdog and under-funded primary opponents are getting into the act as well.

Community newspaper publisher Lisa McCormick, challenging Menendez, calls the incumbent "corrupt and ineffectual." Construction company owner Brian Goldberg, trying to upend Hugin, warns that his opponent has "too many issues that are troublesome."

New Jersey is one of 34 states electing a U.S. senator this fall, and if the opening weeks of the campaign are any indication, it's going to be a real nasty race.

"There's no reason it's going to be anything different than what we've seen so far," said Krista Jenkins, a political science professor at Fairleigh Dickinson University. "Negative campaigning works; as much as people really want to engage in hand wringing. That what you do. You go after your opponent's weaknesses."

Menendez, D-N.J., faces McCormick in Tuesday's Democratic primary. Hugin is being challenged by Goldberg, who unsuccessfully sought his party's Senate nomination in 2014.

The race is being fought in a midterm election widely considered a referendum on President Donald Trump, who had just a 35 percent job approval rating in the Garden State in the last Monmouth University Poll.

"The primary's a prelude," said Menendez, 64. "I can't think of an election that has more consequences about where our country is going and how New Jerseyans fare than what's coming up."

Hugin said Trump isn't going to be the issue.

"The race is Bob Menendez versus Bob Hugin and who's going to be better for New Jersey," said Hugin, 63.

The winners square off on Election Day, Nov. 6. Both Washington-based publications that track congressional races, the Cook Political Report and Inside Elections, rate Menendez as a strong favorite for re-election.

"Fundamentally, Menendez is a Democratic senator in a Democratic state in a Democratic year," said Nathan Gonzales, editor and publisher of Inside Elections.

Looming over the race are Menendez's ethical issues, which Hugin said led him to enter the race.

"We were morally offended that Bob Menendez could possibly be re-elected without serious opposition," Hugin said.

The Senate Ethics Committee "severely admonished" Menendez in April for accepting gifts from a friend and campaign donor, Dr. Salomon Melgen, while intervening with federal agencies on his behalf.

The ethics panel acted after the U.S. Justice Department unsuccessfully prosecuted Menendez on corruption charges. The first attempt ended in a mistrial and, after a judge dismissed several counts, federal prosecutors dropped the rest.

McCormick, too, has gone after Menendez on ethics.

"I wasn't indicted, I'm not a senator for 25 years," McCormick said. "You're involved in politics for a long period of time, you're likely to get corrupted."

She said that if she doesn't beat Menendez in the primary, then a Republican likely will win in the fall.

"We really can't afford to lose a Democratic seat in Congress," said McCormick, 49. "We have to put up better candidates in order not to do that."

Menendez dismissed the concerns.

"Obviously, these people are devoid of any positive ideas and that negativity at the end of the day is not the way I believe at the end of the day people are going to make a decision about who they want to have represent them in the United States Senate and who's going to fight for them every day," Menendez said.

At the same time, Menendez has raised ethical questions about Hugin. Celgene recently was cited by the Food and Drug Administration for making it harder to develop a generic version of its Revlimid cancer drug.

The company under Hugin also paid a $280 million fine to settle charges that it pushed Revlimid and another cancer drug for uses not approved by the FDA.

Goldberg, 45, has launched the same attacks.

"The branding of someone related to big pharma is not a positive branding to have in 2018," he said.

Hugin said he has nothing to worry about.

"There is nothing in my personal life or professional life life that I'm embarrassed of," he said. "I'm proud of what I've done. I'm not running away from anything."

In the primary, McCormick is coming at Menendez from the left, backing a higher minimum wage; Medicare for All, a single-payer health insurance bill that U.S. Sen. Cory Booker, D-N.J., has co-sponsored; and curbs on money in campaigns.

Goldberg is running to Hugin's right, opposing abortion and new gun regulations, backing the Trump tax bill that targeted New Jersey and other high-tax states, and promising to support the president.

Hugin, one of the few financial supporters of Chris Christie's presidential campaign to follow his lead and back Trump, now emphasizes his differences with the president over issues such as Gateway Tunnel funding and preserving the full deduction for state and local taxes.

"You know the Democrats and Menendez are going to tie him to the president in the fall," Goldberg said. "They'll be easily able to say, 'He supported the guy. Now you're saying you're not with him. How can anybody trust you on anything?'"

Hugin said he'll support anyone who puts the Garden State first and oppose someone who doesn't.

"Anyone who says I'm anything but pro-New Jersey is not being fair and accurate," Hugin said. "I will support anybody who supports things that are good for New Jersey."

Menendez and Hugin are financially outgunning their primary challengers, according to recent Federal Election Commission filings.

Hugin lent his campaign $7.5 million, raised $647,847 and had $4.5 million in the bank. Menendez raised $8 million, with $5.6 million in the bank.

Meanwhile, Goldberg raised just $4,688 through May 16 and lent his campaign $3,131. McCormick hasn't reported raising any money.

Jonathan D. Salant may be reached at jsalant@njadvancemedia.com. Follow him on Twitter @JDSalant or on Facebook. Find NJ.com Politics on Facebook.