Gov. Phil Murphy still has a double-digit lead over Republican challenger Jack Ciattarelli, according to a new poll, but Ciattarelli has gained ground in recent weeks due to more GOP voters throwing their support behind the gubernatorial candidate.

Murphy leads Ciattarelli 51% to 38%, according to the Monmouth University survey released Wednesday, while a similar poll last month found Murphy ahead 52% to 36%. Ciattarelli’s backing among Republican voters has jumped from 85% to 91% since then, and more voters said they trust him over Murphy to handle their concerns about taxes.

But less than six weeks from Election Day, with early voting taking place this year and mail-in ballots already arriving at people’s homes, half of those surveyed said they had no opinion about Ciattarelli. That’s despite a growing number of television ads from both campaigns.

“September shifts are not unheard of in New Jersey elections and we see some potential for a single-digit race in these results,” Monmouth pollster Patrick Murray said in a statement. “But we don’t really see movement in the underlying dynamics of this campaign.”

Almost half of New Jerseyans surveyed said they had a favorable impression of Murphy, and 31% said the same for Ciattarelli. That’s an increase from last month, when just 26% said they had a good impression of Ciattarelli.

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Murphy and Ciattarelli, a former state assemblyman from Somerset County, both draw broad support from their own parties. Murphy, a Democrat, leads Ciattarelli 44% to 39% among voters who aren’t aligned with either party, according to the poll. Registered Democrats outnumber Republicans by one million in New Jersey, while about 36% of the electorate are independents.

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

Murphy’s approval ratings have slipped from a high of 71% in 2020, when voters overwhelmingly approved of his coronavirus response, but in the new Monmouth poll, half of voters said they still trust Murphy to handle their concerns about the pandemic. Only 23% said the same for Ciattarelli, who has regularly attacked Murphy’s policies on masking and vaccination.

But 39% of voters surveyed said they trust Ciattarelli more to handle their concerns about taxes, with only 33% saying the same for Murphy. A cornerstone of Ciattarelli’s campaign is taxes, the state’s cost of living, and the economy under Murphy.

Voters are split on who can better help small businesses, with 36% saying Ciattarelli and 34% Murphy, but Murphy leads Ciattarelli 39% to 32% when it comes to jobs and the economy.

Voters are divided on who they trust to handle crime, with 32% saying Murphy and 30% saying Ciattarelli.

In a state where Biden won almost 60% of the vote last year, Murphy’s campaign has sought to link Ciattarelli to Donald Trump. But voters surveyed were mixed on whether they believed Ciattarelli was aligned with the former president: More than a quarter said they feel Ciattarelli does not necessarily agree with the Trump wing, and only says things to keep the support of those voters. About a third said they didn’t know where Ciattarelli stood in terms of the Trump wing.

Overall, Murray said, “Trump himself does not appear to be a driving factor for where this race stands right now.”

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Murphy has described himself as an unapologetic progressive, and 44% of voters surveyed said they believed he was in agreement with that wing of the Democratic Party.

“Being aligned with the polar end of the party’s base plays well within that party,” Murray said. “But that also means whoever has the bigger base wins because there is no appeal to voters in the middle, if such voters even exist anymore.”

The poll of 804 New Jersey registered voters, conducted Sept. 16 to Sept. 20, has a margin of error of plus or minus 3.5 percentage points.