Republicans suddenly see an opening in an unlikely state's Senate race, but Democrats remain confident

• Republicans see a rare opportunity in New Jersey's Senate race.
• Polls show a tightening race between Democratic Sen. Bob Menendez and his Republican challenger, Bob Hugin.
• Democrats remain confident about their chances in the reliably blue state.

In a year when Democrats are talking up the possibility of a "blue wave," Republicans are zeroing in on an unlikely target - New Jersey's Senate race.

The traditionally blue state hasn't elected a Republican to the Senate since 1972. President Donald Trump's approval in the state is just 33%, according to a Quinnipiac University poll last month. Registered Democrats outnumber Republicans by roughly 900,000, according to The New York Times.

Plus, a number of House races in the state are hotly contested in an election year when momentum seems to favor Democrats. In the Senate race, the Democratic candidate is a two-term incumbent who has served New Jersey in Congress since being elected to the House in 1992.

But in this unusual race, polling has shown a tightening battle between Sen. Bob Menendez and his challenger, Republican Bob Hugin, a deep-pocketed pharmaceutical executive and 2016 delegate for Trump who dominated the airwaves early in the race.

The August Quinnipiac poll found that Menendez led Hugin by 6 points, well below his 17-point lead in the previous Quinnipiac survey from March. Weeks prior, a Gravis poll found Menendez with a 2-point advantage.

'Severly admonished'

Why isn't Menendez coasting as Democrats are talking up the possibility of flipping a Senate seat in Texas? Part of the answer is the ethical controversy that has surrounded him for a sizeable chunk of his current term. In 2015, he was indicted by the Department of Justice on corruption charges.

Menendez has vehemently denied the charges against him, and his subsequent trial ended with a deadlocked jury last fall. Earlier this year, the bipartisan Senate Ethics Committee "severely admonished" him for the actions that led to charges.

Then, in a prank call over the summer with a comedian that Trump believed to be Menendez, the president congratulated him for overcoming what he described as a "tough, tough situation" that Trump did not believe was "a very fair situation."

In the Quinnipiac poll, the No. 1 issue for New Jersey voters was "ethics in government," just ahead of taxes and healthcare.

Mary Snow, a Quinnipiac University polling analyst, told Business Insider that Hugin's dominance in the early ad campaign appears to be helping him make his case against Menendez.

"Bob Hugin has deep pockets and has been spending a lot of money on ads specifically targeting Menendez's ethics problems," Snow said. "And that became a central theme in those ads. When we came out with that poll, Menendez wasn't airing any of his own ads, so Hugin had a wide canvas. Sen. Menendez's ethics issues were weighing on New Jersey voters."

But Snow cautioned against viewing Menendez as being in any serious trouble of defeat, at least as of right now, pointing to the multiple "fundamentals" in his favor, such as being in a blue state in an election year ripe with Democratic momentum.

Hugin, as of the end of June, gave more than $15 million to his campaign, which had spent nearly $9 million up until that point. Integrity NJ, a pro-Hugin Super PAC formed by former Republican Gov. Chris Christie's allies, has helped in the ad arena as well. Last week, the Super PAC launched a more than $1 million ad buy on New York City-area broadcast channels.

Menendez's side has started to ramp up its over-the-air campaign. The Democratic Senatorial Campaign Committee recently made a six-figure coordinated ad buy with the Menendez campaign to begin the fall sprint. On Tuesday, it was announced that 2016 Democratic presidential nominee Hillary Clinton will participate in an October fundraiser for Menendez.

Though the race has tightened since the spring, Democrats remain highly confident their candidate will be able to pull out a victory in November. They've taken issue with Hugin's pharmaceutical career at a time when the industry is overwhelmingly unpopular with Americans.

This week, The Times published an extensive look into Hugin's career at Celgene, the pharmaceutical company where he served as chief executive for six years. The Times wrote that Celgene's "aggressive promotion" of a pair of drugs while Hugin was a top executive revealed "many of the controversial financial and legal tactics that have tarnished the industry's reputation, from marketing drugs for unapproved uses to raising prices and fighting off generic competitors."

"While former pharma CEO Bob Hugin has already spent over $11 million on TV and is using the fortune he made raising the costs of prescription drugs for cancer patients to try to buy the Senate seat, the Menendez campaign smartly held their resources until their ads would have maximum impact in the closing weeks of the election," David Bergstein, a spokesman for the DSCC, told Business Insider in a statement.

Menendez has focused his campaign on both his legislative record and his efforts to combat Trump administration policies.

Republicans are seeking to paint him as a "credible alternative" to Menendez, said Phil Cox, chairman of Integrity NJ. Another objective for Republicans is making Hugin a more well-known quantity. Quinnipiac found in August that 54% of New Jersey voters did not yet know him.

"As an incumbent, you're fully defined, you're stuck in the low-40s on the ballot, and undecided voters don't like you," Cox told Business Insider of Menendez. "You've got a big problem."

Cox, a former executive director of the Republican Governor's Association, said the key to the race is whether it is focused on Menendez - not part of a larger, national context.

"I think the Democrats will hang their hats on the national environment right now favoring Democrats, it's a Democratic state, in a Democratic year, Cox said, adding that "if this race is about Menendez at the end of the day, Hugin wins - even in this environment."