Clinton won the state with 55.5% of the vote over Trump's 41.35%, or a 14-point margin. Despite her victory in the state, Clinton's vote share was slightly poorer than the vote shares President Barack Obama got from the state in 2008 and 2012. This was the first time since 1976 that New Jersey did not vote for the same candidate as neighboring Pennsylvania, and the first time since 1932 that New Jersey voted Democratic while Pennsylvania voted Republican. Donald Trump became the first Republican to win the White House without carrying Somerset County since Benjamin Harrison in 1888.
New Jersey's presidential primaries were on June 7, 2016, with the Democratic, Republican, and Libertarian parties participating. Registered members of each party could only vote in their party's primary, while voters who were unaffiliated could choose any 1 primary in which to vote.
Hillary Clinton's 55.5% of the vote was 2.9% less than Barack Obama's win in the state in 2012. Overall, the trend from 2012 to 2016 was that suburban areas of central and northern New Jersey voted more Democratic, while the shore and southern New Jersey voted more Republican. Clinton's most notable improvements over Obama in 2012 were seen in Union, Somerset, and Morris Counties. In Morris, Clinton came within 5% of winning the county, which had not voted for a Democratic presidential candidate since 1964. Clinton's stronger performance in the suburban towns of north-central New Jersey, such as Summit, Westfield, and Bridgewater, helped her narrowly win the 7th congressional district.
On the other hand, southern New Jersey, especially Cumberland County and Salem County, voted significantly more Republican than they had in 2012. For example, even though Cumberland County voted Democratic in both 2012 and 2016, Clinton won it by just 6%, whereas Obama won it by nearly 24% in 2012. Donald Trump became the first Republican to win Gloucester County since George H. W. Bush in 1988. He also flipped the swing county of Salem, which he won by a commanding 15-point margin, signaling its shift to the right. Additionally, the four shore counties of Monmouth, Ocean, Atlantic, and Cape May all voted more Republican than they had in 2012. While Mitt Romney had won these four counties collectively by around 6% in 2012, Trump won them by 17% in 2016.