How did they become “deep Blue States”? For a long time New Jersey was a Repub stronghold/swing State post WWII until the Sink Emperor came along.
Demographics is destiny.
New Jersey is one of the most suburban and most educated states in the U.S.
Highly educated suburbs (especially in the Northeast Corridor) have shifted Democratic nationwide since the 1990s.
Key areas that moved blue:
North Jersey suburbs (Essex, Bergen, Hudson)
Central Jersey suburbs (Middlesex, Mercer, Somerset)
Philly suburbs on the Jersey side (Camden, Burlington)
NJ has a large public-sector workforce:
Teachers
Police
Transit workers
Government employees
About 23–25% of New Jersey’s population is foreign-born (i.e. immigrants):