The 1978 NJ Senate election, a contest between former New York Knicks Star Bill Bradley and Onetime Governor Ronald Reagan aid Jeff Bell resulted in the Democratic Party picking up a seat held by longtime liberal Republican Senator Clifford Case
The fundamental reason Democrats were able to pick up this seat is because Case, no friend to the New Jersey establishment nor the ideological base of the party, was bested in a contested primary by the staunch conservative & trickle down economics proponent Jeff Bell.
This led to Bradley, a Rhodes Scholar who had been campaigning for NJ Dem politicos for a while, having an opening to win the seat in the historicly red leaning swing state.
an Opening where, after winning the primary with ease—considering the staunch conservatism of bell & his long publicized connections to the state—he functionally walked into the seat held by Case with a 12% win.
In his win, Bill Bradley arried 15/21 Counties to Jeff Bell's 6/21 Counties, 31/40 Legislative Districts to Bell's 9/40 LDs and 13/15 Congressional Districts to Bell's 2/15