Nearly a month after winning the Republican primary, former U.S. Attorney Chris Christie maintains a double-digit lead over Gov. Jon Corzine (D), a new Public Policy Polling (D) survey finds.

General Election Matchup
Christie 51
Corzine 41
Undecided 9

Typically, New Jerseyans are late making up their minds in campaigns, owing to the fact that the state has no major television market of its own and coverage tends to be minimal among New York and Philadelphia outlets. But the survey found that 70 percent of voters are "solidly committed" to their candidate, with only 30 percent saying they could change their mind. Breaking those numbers down, Republicans tended to be more committed to their choice (81 percent), while more than a third of Democrats said they still could change their minds.

Christie is still unknown to a quarter of state voters, while Corzine maintains an upside-down favorability rating.

Favorability Ratings
Corzine 36/56
Christie 43/33

One promising sign for the incumbent: Corzine leads Christie 56-40 in the 201 area code. That zone covers most of Bergen County, which has proven to be the bellwether in state elections. Bergen is in the northeastern part of the state, home to many New York commuters.

The automated telephone survey of 1,094 likely voters was conducted June 27-29, and had a margin of error of +/- 3 percent.

The next critical step in this race will come later this month, when the candidates must choose running mates. It's the first time in a New Jersey gubernatorial election where candidates will have a running mate, with the creation of a lieutenant governor position years ago.