Is New Jersey now a swing state?

One of the biggest surprises of the election was how close the presidential race was in New Jersey. A state that President Joe Biden had won by 16 points four years ago gave Vice President Kamala Harris only a six-point margin of victory.

It is too early for an in-depth analysis of what led to the decline in Democratic support. New Jersey won’t even finalize its election results for several more weeks. It is clear, however, that N.J. was not unique among the blue states.

While support for the Democratic presidential nominee dropped by 10 points in N.J., it also dropped by eight points in California and Massachusetts and 11 points in New York. New Jersey’s decline stood out because it appeared to move the state from safely blue to swing state status, while the even larger drop in support in New York still resulted in a 12-point Harris advantage.

It is also clear that New Jersey’s surprisingly close presidential election was primarily the result of fewer Democratic votes rather than more Republican ones. Harris received 15 percent fewer votes in the Garden State than Biden had in 2020, while President-elect Donald Trump received 4 percent more than in 2020.

Here too, other blue states saw comparable or greater declines in votes for Harris and increases in support for Trump. Harris received 15 percent fewer votes than Biden in Hawaii, 16 percent fewer in New York and 18 percent fewer in California. Trump’s vote grew by 6 percent in Massachusetts and Vermont; 7 percent in Delaware, New York and Rhode Island; and 12 percent in the District of Columbia.

The data does not suggest that New Jersey is shifting dramatically to the right. However, a realignment does appear to be taking place that reflects some of the national demographic trends.

Trump exceeded his 2020 vote totals in 11 of New Jersey’s 21 counties, while holding constant or declining in the other 10. His largest vote increases were in five of the state’s most Democratic and racially, ethnically and economically diverse counties — Essex, Hudson, Middlesex, Passaic and Union — where he saw double-digit growth. This is consistent with the national shift towards Trump among working-class voters of all races and ethnicities. Conversely, Trump performed worse than four years ago in some of the state’s whitest and most Republican counties — Cape May, Hunterdon and Salem.

These voting trends predate 2024. In the 2020 election, Trump’s greatest percentage increases in support came from the same heavily Democratic and diverse counties, while Biden’s greatest increases relative to Hillary Clinton were in the state’s most Republican and least diverse counties.

Four additional factors likely affected the New Jersey’s election results.

First, the perception of the state as safely Democratic at the presidential level and the lack of competitive House and Senate races may have depressed Democratic voter turnout. New Jersey’s 7th Congressional District, the only one perceived as competitive, saw 34,000 more residents vote than the district with the next-largest voter turnout.

Second, Trump was able to turn out what appear to be low-propensity voters, many of whom do not vote GOP down-ballot. Trump received 194,000 more votes than Curtis Bashaw, New Jersey's GOP Senate candidate, and 139,000 more votes than the Republican House candidates. In contrast, Harris received only 59,000 more votes than Rep. Andy Kim, the Democratic Senate candidate, and 104,000 more votes than the Democratic House candidates.

Third, the 2018 implementation of automatic voter registration enfranchised low-propensity voters. The number of registered voters increased by 13 percent in the six years following adoption of automatic voter registration, versus 8 percent in the prior six years.

Fourth, the temporary pandemic-era mailing of paper ballots to all registered voters in 2020 made voting easier. Voter participation grew to 70 percent in 2020 vs 67 percent in 2016.

In 2020, the greater enfranchisement and ease of voting appear to have helped Democrats, who saw historic levels of voting by the young. This year, the greater enfranchisement may have helped Republicans, who benefited from Trump’s appeal to low-propensity voters, while overall voting rates fell to 63 percent as ballots were no longer automatically sent to all registered voters.

Julia Sass Rubin is on the faculty of the Edward J. Bloustein School of Planning and Public Policy, Rutgers University-New Brunswick, where she also serves as the associate dean of academic programs and director of the Public Policy Program.