An interesting post at 538: "In Blue New Jersey, Red Spots May Be Sign of the Past."
I live in the northern suburbs, where the schism between moderates and a rightward-shifting GOP has been obscured by geographic proximity to the more conservative, fairly rural northwestern section of the state; hence, my congressman, Scott Garrett, is one of the most conservative Republicans in Congress. Meanwhile, other parts of Bergen County, further south and east, are virtually guaranteed to have a liberal Democrat in Congress.
Here's my piece from a few months ago on the state's center-right governor and how his combative style has helped him appeal to conservatives nationwide despite his substantive differences with them.