The 2020 Presidential Election in New Jersey, a Contest between Former Vice President Joe Biden and Incumbent President Donald Trump resulted in the second best performance for a Democrat since 1964 in the Garden State. Only surpassed by Obama's reelection in 2012.
With the two most dominant Issues of the day being the COVID-19 Pandemic and the Economic effect of lockdowns the Deep Blue State's prioritization of the former - in addition to the deep unpopularity of the incumbent President handed the overall 2020 Victor the state.
There was also the issue of Criminal Justice reform which took a position of second most prominent issue in this election after the murder of George Floyd. New Jersey's state government past some reforms a few month after this event occured (https://www.nj.com/news/2020/10/murphy-signs-criminal-justice-reform-bills-but-says-there-is-still-much-to-be-done.html)
But at the end of the Day, While these issues expanded Biden's win, the reason that he won was because New Jersey is a deep Blue state.
Considering 2012 is an unrepresentative election due to the effect of Huricaine sandy, Comparing the results to the 2008 Presidential election is the best case study to understand the shifts under the hood in NJ.
From this it showcases the national trends throughout the country, Educated Suburbs got significantly bluer while minorities, especially Hispanics got redder in this election.
When compared to 2008 certain municipalities (Union City & North Bergen) stand out as they have strong urban political machines which limited the Hispanic swing, while cities like Paterson and Newark that lack such a strong urban political machine Swung more Republican than Union City & North Bergen.
In his 2020 win, Joe Biden won 9/12 Congressional Districts to Trump's 3/12 CDs, 14/21 Counties to Trump's 7/21 Counties, and 29/40 State legislative Districts to Trump's 11/40 LDs