The New Jersey governor’s race remained too close to call Wednesday, with Democratic Gov. Phil Murphy and Republican Jack Ciattarelli trading the lead, separated by less than 1% of roughly 2.4 million ballots cast, according to the Associated Press.

Polls taken in the weeks before the election projected Mr. Murphy with a comfortable lead, and Republicans said the closer-than-expected result was a sign of voter frustration.

Election...

The New Jersey governor’s race remained too close to call Wednesday, with Democratic Gov. Phil Murphy and Republican Jack Ciattarelli trading the lead, separated by less than 1% of roughly 2.4 million ballots cast, according to the Associated Press.

Polls taken in the weeks before the election projected Mr. Murphy with a comfortable lead, and Republicans said the closer-than-expected result was a sign of voter frustration.

Election officials in several counties were still processing vote-by-mail ballots, which under state law must be counted if they are postmarked by Tuesday and received by Nov. 8. State officials said Monday that nearly 500,000 mail ballots had been received.

Monmouth University Polling Institute Director Patrick Murray said the outstanding mail votes likely would favor Mr. Murphy because more Democrats requested ballots than Republicans.

The race centered largely on taxes. Mr. Ciattarelli, a former state assemblyman, has criticized Mr. Murphy’s fiscal policies and promised to cut state spending. Mr. Murphy, a former Goldman Sachs executive who was first elected in 2017, raised taxes on millionaires and expanded educational programs.

Mr. Murphy campaigned on his record in office, touting the legalization of marijuana and increases to the state’s minimum wage. He said he provided stable management during the Covid-19 pandemic, and Monmouth polls showed his job approval rating remained above 50% since the virus arrived in March 2020.

Mr. Ciattarelli has criticized Mr. Murphy’s requirement that school students wear masks while in the classroom and faulted the governor for a policy early in the pandemic that allowed nursing homes to accept Covid-19 patients from hospitals. Mr. Murphy said the masking policy is needed to keep children safe and called the coronavirus nursing home deaths a tragedy.

Speaking to supporters just after midnight, Mr. Murphy said, “We’re going to wait for every vote to be counted, and that’s how our democracy works.”

Republican candidate Jack Ciattarelli greeted supporters in a hotel ballroom at his watch party Tuesday evening in Bridgewater, N.J.

Photo: Spencer Platt/Getty Images

New Jersey GOP Chairman Bob Hugin said the results showed that voters in the state were frustrated with government overreach and that the state’s high taxes were “an underlying, fundamental issue that’s always on the front of Jersey voters’ mind.”

Mr. Murray said voters’ concerns about Covid-19 waned in the weeks leading up to the election, leaving an opening for Mr. Ciattarelli’s core campaign theme.

No Democrat has won re-election as governor of New Jersey since 1977.

Registered Democrats outnumber Republicans by more than one million in the Garden State, according to the New Jersey secretary of state’s office. That is up from a Democratic advantage of around 700,000 voters in 2009, when Republican Chris Christie defeated Jon Corzine’s bid for a second term.

In recent weeks, both President Biden and Vice President Kamala Harris

appeared with Mr. Murphy. Mr. Biden easily carried the state in the 2020 presidential election.

Ben Dworkin, director of the Rowan University Institute for Public Policy and Citizenship, said the election was Mr. Murphy’s to lose.

“There’s a drag from Joe Biden’s low approval ratings. And the craziness that’s gone on in Washington has depressed Democratic enthusiasm and energized Republicans,” he said.

Julie Roginsky,

a Democratic consultant who worked for Mr. Murphy during his 2017 campaign, said he could have had a stronger showing if he had focused more on affordability and less on national trends.

“It turns out that you can’t ignore the number-one issue that voters in New Jersey have had for the last 30 years—affordability and property taxes—and expect to win,” she said.

Write to Jimmy Vielkind at Jimmy.Vielkind@wsj.com