Also, I would add that in general New Jersey in non-federal races is much swingier than its federal PVI lets on. Since 1981 pretty much all elected Dem governors have been flops who served 1 term or less, and many people in the state who vote D federally b/c they think the national GOP is bonkers vote GOP in state races b/c of more local issues like crime and property taxes. Given those factors, a Murphy win that just about matches Clinton's margin would actually be fairly good, and any extra margin he gets would likely be a result of the far-more-toxic-than-usual national Republican administration driving up D turnout and driving down R turnout.
I would say Guadagno has been trying to distance herself from Christie (reminding people that she's literally not him in debates or just completely ignoring him), but not super successfully given Murphy has several ads calling her a third term of Christie. But when it comes time to vote there is a chunk of voters who will think that despite their misgivings with Christie's corruption and virtual abandonment of the state, a vote to give Democrats total control of Trenton is a vote to raise their already-high taxes and thus will come home to Guadagno. Not enough to change the outcome, mind you, but enough to make it at typical New Jersey 55/56% D - 41%/42% R race.
