You think that the 72% approval rating wouldn't carry over to a vote for president?Can Chris Christie separate himself from his party to get New Jersey to vote Republican for the presidency for the first time since 1988? Last year on record N.J. voted for a Republican nominee who did not win the presidency was when Gerald Ford carried the state and was unseated by Jimmy Carter. But Carter won primarily through the south, taking all of the former confederate states except Virginia.
In 2012, New Jersey was one of about a half-dozen states which actually had a Democratic shift for President Obama. He won it in 2008 by D+15.53. With re-election in 2012, the president carried N.J. by D+17.68. In 2008, N.J. was 8.27% bluer than how the country voted. (Obama beat John McCain by D+7.26.) In 2012, N.J. was 14.00% bluer relative to the national margin. (Obama defeated Mitt Romney by D+3.68.)
If we were to see a President Chris Christie, the way the map shakes out nowadays is that he'd have to become the first elected without carriage of his home state since Richard Nixon claimed New York as his residency, while it supported losing Democrat Hubert Humphrey, as the 37th president was also the GOP pickup winner of Election 1968.
For New Jersey to carry for an elected Chris Christie it would have to be either arbitrary (which I wouldn't buy into) ... or it would turn out to become a 40-state landslide (400-plus vote) victory in the Electoral College. States which vote like N.J. would also become flipped from blue to red (to elect Chris Christie). And these are populous states, in the Top 10 and Top 20, which over the last 100 years have colored the same at least in 80 percent of such elections. Given the current state of the Republican Party ... and how people are handling their presidential votes (which very much involves in chosing red or blue) ... I don't think it would happen. And since 1992, no candidate has carried more than 32 states (as won that year when Bill Clinton unseated George Bush and flipped N.J. into his and the Democratic Party's column).
Chris Christie should have no problem getting re-elected this year as the 55th Governor of New Jersey. Dating back to 1977, the state has been in the habit of electing governors from the party opposite a sitting president. And Christie's stance, with what he has said about Congress, has enough of a populous appeal that the Democrats likely won't have a challenger who is much of a challenge. In 2009, Christie unseated Jon Corzine with a statewide margin of about 5 percentage points. This year, with re-election, it will increase substantially.
Now, all of what I said could be reconsidered if Chris Christie switched from the Republican to the Democratic party. Which I don't believe would feasibly happen.