New Jersey Gov. Phil Murphy has a wide lead over Republican opponent Jack Ciattarelli, according to a new poll, but Murphy’s approval ratings have slipped and many voters still don’t know who the GOP nominee is less than five months before the general election.

In the first public survey of New Jersey voters since Ciattarelli won the June 8 GOP primary, Fairleigh Dickinson University found that half the state’s voters approve of Murphy’s job performance. That’s down from 57% in a Monmouth University poll in May.

Ciattarelli, a former state assemblyman, beat three Republican primary rivals this month. But 70% of New Jerseyans surveyed said they don’t know enough about Ciattarelli to have an opinion of him, while 17% said they had never heard of him. Only 16% percent viewed him favorably.

Murphy leads Ciattarelli by 15 percentage points, according to the poll, 48% to 33%.

“Ciatterelli has his work cut out for him,” Dan Cassino, a pollster and Fairleigh Dickinson professor of government, said in a statement. “Being unknown is better than being disliked, but running ads in New Jersey to build up awareness is an expensive proposition.”

» READ MORE: Jack Ciattarelli wants to make his campaign against Phil Murphy about who the real ‘Jersey guy’ is

Murphy and Ciattarelli draw broad support from their parties, with 84% of Democrats saying they’d support Murphy and 77% of Republicans backing Ciattarelli.

But registered Democrats outnumber Republicans by one million in New Jersey. And the Republican ticket drew the same support in the poll whether voters were asked about Ciattarelli specifically or given the choice of an unnamed GOP candidate.

“In order to win statewide, Republican candidates need to outperform a generic candidate,” Cassino said. “So far, Ciatterelli just isn’t doing that.”

Even among Republicans surveyed, Ciatterelli is little known: 35% said they had a favorable view of him, while 48% had no opinion and 9% had not heard of him.

Among independent voters, 36% said they approve of the job Murphy is doing, while 41% disapprove.

Murphy’s approval ratings remain higher than in the days before COVID-19, when many voters still didn’t know who he was. But the pandemic boosted both his visibility and popularity, with voters widely approving of his early pandemic response. At one point last year, pollsters measured his approval ratings as high as 71%.

“Governor Murphy is not focused on polls but on leading our state to the other side of the pandemic,” his campaign spokesperson, Jerrel Harvey, said Monday.

If he succeeds in winning a second term in November, Murphy would be New Jersey’s first Democratic governor in decades to win reelection.

» READ MORE: Phil Murphy gave New Jersey progressives what he promised. Now they’ve got his back for reelection.

Asked how former President Donald Trump should be treated when he visits his Bedminster golf course this summer, 42% of respondents said he should be ignored. About a third said he should be welcomed, and 24% said he should be discouraged from coming.

Trump loomed over the GOP primary race, with two candidates vying for — and splitting — his most fervent supporters, a reflection of his enduring popularity among New Jersey Republicans.

The survey of 803 New Jersey registered voters, conducted June 9 to June 16, has a margin of error of plus or minus 3.9 percentage points.