Chris Christie is really, really popular — by New Jersey standards.

Christie’s 56 percent approval rating in a Fairleigh Dickinson University poll this week may not seem all that remarkable, but when it comes to New Jersey, it is.

New Jersey Governor Chris Christie (Jonathan Ernst/Reuters)

The reason: New Jersey voters are notoriously tough on their politicians.

Consider this:

* President Obama hasn’t gone higher than 56 percent approval in Quinnipiac polling of the state since June 2009 — slightly after he took office on a high note.

* Sen. Bob Menendez (D) hasn’t cracked 50 percent approval in at least the last two years (and might never have done it).

* The highest approval that Sen. Frank Lautenberg (D) has ever recorded, according to Quinnipiac pollsters, is 55 percent. That was in the year 2000, before he retired from the Senate and then made a comeback.

* Even at his most popular (after he suffered serious injuries in a car accident and cut taxes early in 2007), former governor Jon Corzine (D) barely cleared 50 percent approval. When he was in the Senate the first part of the decade, his approval only climbed into the high-50s for a brief time.

* Sen. Robert Toricelli (D-N.J.) never cracked 50 percent in his one term prior to succumbing to scandal.

* The highest approval rating Quinnipiac has measured for a governor since it began polling the state in 1996 was Gov. Christine Todd Whitman (R), who once earned a 62 percent approval rating. That’s only three points better than the 59 percent Christie posted in Q’s most recent poll.

When we wrote about the 10 most popular governors in the country (and ranked Christie 2nd), his approval rating didn’t necessarily match up with the 60- and 70-percent-plus approval ratings posted by other governors (including No. 1, New York’s Andrew Cuomo).

But given how tough it is to please voters in New Jersey, the mid-to-high 50s is a significant accomplishment.

Christie said this week that he doesn’t know whether he’ll seek re-election in 2013 (he seems to have his eyes on another prize), but if he did, you have to wonder whether Democrats would even be able to field a top-tier candidate.

One thing’s for sure, though: His record as governor and the way he has been received in his home state is nothing but a plus when it comes to the GOP veepstakes.