New Jersey is a Democratic-leaning state, and it’s getting bluer by the month.

Democrats have registered voters at a faster pace than Republicans in the Garden State. But the GOP still maintains pockets of control in some counties.

Republicans are outnumbered by registered Democrats by nearly 1 million people (976,835, to be exact), according to the latest statistics from the state’s Division of Elections. As of the end of September, New Jersey had 2,307,937 registered Democrats and 1,331,102 Republicans.

Over the past year, Democrats added more than double the number of registered voters (108,615) compared to the GOP (53,311), according to the data.

However, registered Republicans outnumber Democrats in six of the state’s 21 counties, and there are a few other counties that are pretty evenly split. Also, Republicans out registered the number of new Democrats in six counties from this time last year, including in three counties where the number of Ds outweigh the Rs.

The largest number of New Jersey voters — 2,378,040 to be exact — have not formally claimed any party affiliation.

“Twelve years ago, Democrats had a 290,000 vote plurality over registered Republicans statewide," said Ben Dworkin, director of Rowan University’s Institute for Public Policy and Citizenship.

“Today, it’s one million. All these new registered Democrats have to live somewhere,” he said. "Not all are living in Newark and Princeton. They are living in Burlington County and Somerset County and eastern Morris County, and they are turning what the political class would have defined as safe Republican districts into actually competitive districts.”

While President Donald Trump lost New Jersey by 14 points to former U.S. Secretary of State Hillary Clinton in 2016, nine counties tipped in the Republican’s favor. And in Democratic Gov. Phil Murphy’s landslide in 2017′s governor’s race, eight counties went for Republican Kim Guadagno.

Is the Democratic uptick part of the so-called Trump effect in New Jersey? Not entirely, Dworkin argued.

“This has been going on long before Trump started," he said. "The surge really started with the Obama/Clinton primary in 2008 and has continued since then. Chris Christie’s unpopularity has helped. That’s been followed up by the unpopularity of Donald Trump in this state.”

So far, more than 180,000 people have voted by mail across the state, according to a spokeswoman for the state’s Division of Elections. Additionally, NJTV News reported nearly 600,000 vote-by-mail ballots had been requested as of the end of October, and that 275,429 went to Democrats and 149,540 to Republicans, according to the report. The rest were sent to unaffiliated voters.

Here is a county-by-county breakdown of which political party rules in each of New Jersey’s 21 counties and how much each party gained since this time last year.

Atlantic County

Democrats: 64,870

Republicans: 49,063

Unaffiliated: 73,939

Clinton won by 7 points against Trump in Atlantic County and the county went for Phil Murphy in 2017. But the county went for Republican Gov. Chris Christie in 2009 and 2013.

How the county has changed since the last election: Atlantic added 2,957 Democrats and 1,932 Republicans from September 2018. Unaffiliated voters added 1,121 new people.

Bergen County

Democrats: 232,543

Republicans: 135,627

Unaffiliated: 259,413

Bergen County is the most populated county in the state with 940,000 people, according to 2016 U.S. Census estimates. Clinton carried the county by 13 points in 2016 and Democrats outnumber Republicans by more than 78,000 registered voters.

How the county has changed since the last election: Bergen added 12,961 voters in the Democratic Party in the past year and 5,692 Republicans. There’s also 5,516 more unaffiliated voters.

Burlington County

Democrats: 120,069

Republicans: 79,555

Unaffiliated: 118,056

Clinton won in Burlington by nearly 15 points, and gave Murphy and 18,000-vote advantage. But the county twice tipped in Christie's favor.

How the county has changed since the last election: Burlington added 3,596 more Democrats this year and 1,517 new Republicans. There are 1,848 fewer unaffiliated voters.

Camden County

Democrats: 171,686

Republicans: 55,007

Unaffiliated: 138,190

Clinton carried the county by more than 32 points, and Murphy enjoyed more than a two-to-one advantage.

How the county has changed since the last election: Camden County has 7,834 more Democrats compared to this time last year and 2,731 new Republicans. There are 1,822 additional unaffiliated voters.

Cape May County

Republicans: 28,946

Democrats: 16,893

Unaffiliated: 25,341

Republicans reign supreme in Cape May County, where registered Democrats are outnumbered nearly two-to-one. Trump carried the county by nearly 20 points.

How the county has changed since the last election: In Cape May, the number of new Democratic registrants (387 people) outpaced new Republicans (33 people). Unaffiliated voters dropped off by 410 people.

Cumberland County

Democrats: 30,546

Republicans: 18,603

Unaffiliated: 39,798

There’s almost 12,000 more registered Democrats than Republicans in Cumberland County. Clinton won by 6 points.

How the county has changed since the last election: Cumberland added 1,167 more Democrats and 845 more Republicans compared to this time last year. Unaffiliated voters dropped off by 2,492.

Essex County

Democratic: 274,385

Republican: 53,013

Unaffiliated: 200,719

Essex County is home to the state’s largest city, Newark. It has the largest Democratic-Republican gap in the state and the largest Clinton-Trump voting gap in 2016. Clinton won in Essex by nearly 57 points.

Essex is also one of only two counties that went blue in the 2013 gubernatorial race, which Republican Christie won by about 22 points.

Two years ago, Essex gave Murphy more votes than any county: 129,470 to Guadagno’s 30,633.

How the county has changed since the last election: Essex added 14,110 more Democrats and 2,750 Republicans. Unaffiliated voters also jumped by 7,649 registrants.

Gloucester County

Democrats: 83,141

Republicans: 48,469

Unaffiliated: 81,392

Registered Republicans rank last against their Democratic and unaffiliated counterparts in Gloucester County, but Trump clinched the county by a slim margin in 2016.

How the county has changed since the last election: Gloucester added 2,089 Republicans to its rolls and 1,419 Democrats. Unaffiliated voters dropped by 1,305 people.

Hudson County

Democrats: 208,999

Republicans: 37,008

Unaffiliated: 129,585

Hudson County is the most densely populated county in New Jersey and is home to Jersey City, the state’s second-largest city. Its voters went against Christie in 2013 and four-to-one for Murphy four years later.

Clinton won by her second-largest margin, 52 points, in Hudson.

How the county has changed since the last election: Hudson has 11,021 more newly registered Democrats, 2,889 more Republicans and 6,113 more unaffiliated.

Hunterdon County

Republicans: 38,861

Democrats: 24,498

Unaffiliated: 35,719

It’s a Republican county but Democrats have made small (emphasis on “small”) gains here.

Trump won by nearly 14 points, and Guadagno got nearly 10,000 more votes than Murphy.

How the county has changed since the last election: Hunterdon has 806 new Democratic registrants compared to 355 new Republicans. The number of unaffiliated registrants dropped by 93 people.

Mercer County

Democratic: 109,953

Republican: 38,762

Unaffiliated: 100,531

Home to the state capital, Trenton. The residents are mostly Democrats. Clinton trounced Trump by 37 points in the county in 2016.

How the county has changed since the last election: Mercer added 5,576 Democrats in the past year. Republicans gained 2,152 new registrants and unaffiliated voters went up by 2,560 people.

Middlesex County

Democratic: 225,695

Republican: 81,936

Unaffiliated: 221,018

Middlesex County looks a lot like its neighbor Mercer County when it comes to registered Democrats and Republicans. The only difference is the numbers are about doubled (tripled in the case of new Democrats).

How the county has changed since the last election: Middlesex Democratic registrants spiked by 14,893 people and Republicans grew by 5,778 people. There are 3,060 unaffiliated voters in Middlesex County compared to a year ago.

Monmouth County

Democrats: 128,776

Republicans: 128,121

Unaffiliated: 198,930

Long seen as a Republican stronghold, Democrats actually have a slim 655-voter edge among registered voters in Monmouth.

But that margin is shrinking. In 2017, it had about a 3,000-Democratic-voter edge. Also, new GOP registrants outpaced Democrats compared to this time last year.

Murphy, a Democrat, lost the county to his Republican rival, Guadagno, by more than 22,000 votes. Murphy and Guadagno are both Monmouth County residents.

How the county has changed since the last election: In Monmouth, there are 5,274 new Republicans and 3,259 new Democrats. Unaffiliated voters dropped off by 3,385 people.

Morris County

Republican: 129,175

Democratic: 100,049

Unaffiliated: 134,605

Morris County has the second-largest Democratic vs. Republican voter gap in the state, with the GOP in the lead. Registered Republicans lead their Democratic counterparts by nearly 30,000 voters. The county went for Trump by 4 points.

Republicans are dominate, but Democrats again added more new voters to their rolls.

How the county has changed since the last election: Morris has 4,452 more Democrats, compared to 1,079 new Republicans. There are 1,240 fewer unaffiliated voters.

Ocean County

Republican: 142,847

Democrats: 88,434

Unaffiliated: 178,650

Ocean County is solid red. It’s the county with the most registered Republicans. There are more than 54,000 registered Republicans in Ocean than there are Democrats.

Trump won by his largest margin in New Jersey in Ocean, defeating Clinton by 33 points.

How the county has changed since the last election: Ocean again also added more Republicans than Democrats in the past year. There are 7,216 new GOP voters compared to only 1,458 new Democrats. Unaffiliated voters dropped off by 3,833.

Passaic County

Democrats: 124,807

Republicans: 63,652

Unaffiliated: 131,293

There are about twice as many registered Democrats living in Passaic County than Republicans. Clinton won in the county by 22 points.

How the county has changed since the last election. Passaic County has 6,272 more Democrats this year and 2,392 new Republicans. There are 851 more unaffiliated voters.

Salem County

Democrats: 14,537

Republicans: 11,946

Unaffiliated: 19,637

Salem County is the state’s least populated county, with only about 65,000 people. Registered Democrats outnumber Republicans. But not by much and the latter added more voters.

Trump won in Salem by 15 points.

How the county has changed since the last election: Salem has 808 new Republicans and 577 new Democrats. Unaffiliated registrants went up by 232 people.

Somerset County

Democrats: 80,342

Republicans: 62,664

Unaffiliated: 96,872

Democrats hold a slight advantage here. The county supported Christie twice, but went for Clinton over Trump by 13 points.

How the county has changed since the last election: Somerset County had 5,293 new people register with the Democratic Party in the last year and had 2,889 people sign up with Republicans. Unaffiliated went up by 1,409 people.

Sussex County

Republican: 44,443

Democratic: 22,239

Unaffiliated: 39,068

Republicans outnumber Democrats by more than two-to-one in what is considered a rock-sold Republican county. Trump carried the county by nearly 30 points.

Republicans also added more people to their rolls in the past year.

How the county has changed since the last election: Sussex has 1,142 new people registered with the GOP compared to 805 Democrats. Unaffiliated voters, meanwhile, dropped off by 1,479 people.

Union County

Democrats: 166,271

Republicans: 52,991

Unaffiliated: 126,133

There are more than 113,000 more registered Democrats living in Union County than there are Republicans.

How the county has changed since the last election: Union County added 8,602 new Democrats in the past year and 2,155 new Republicans. Unaffiliated voters added 1,892 people.

Warren County

Republicans: 30,513

Democrats: 19,204

Unaffiliated: 29,151

Republicans outpace Democrats by about 11,300 voters in Warren County, where Trump won by 25 points.

How the county has changed since the last election: Warren County added voters in all three categories in the past year, with Republicans outpacing the rest. There are 1,299 new to the GOP and 1,170 new Democrats. Unaffiliated registrants have 853 potential new voters.

NJ Advance Media staff writer Brent Johnson contributed to this report.

Matt Arco may be reached at marco@njadvancemedia.com. Follow him on Twitter @MatthewArco or Facebook.

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