As New Jersey Democrats prepare for a visit from a popular President, a new Monmouth University/Gannett New Jersey poll has Republican Christopher Christie leading Gov. Jon Corzine by eight points, 45%-37%, and suggests that Barack Obama's visit "may do little to help" Corzine win a second term.

Christopher Daggett, a former state Environmental Protection Commissioner running as an independent, is at 4%.

Just 54% of likely voters say they have definitely made up their minds, and if leaners are taken out of the numbers, Christie's lead goes to 37%-33% -- just a four point advantage.

Corzine's greatest problem is his favorability rating: upside-down at 38%-47%.  A January Monmouth/Gannett poll had Corzine at 49%-38%.

"There is evidence that Corzine's ratings have taken a hit from the state budget process.  On the other hand, the Democrat's decision to air an attack ad may be putting a dent in the Christie armor," said Patrick Murray, director of the Monmouth University Polling Institute.  "Favorability ratings tend to be leading indicators of where an election is headed.  At this stage, these numbers can be more meaningful to the campaigns than the horse race itself."

Christie has a 43%-24% favorable rating, but Murray says "there are some warning signs that the Republican should keep an eye on. "

"While the GOP nominee's favorable rating has remained basically steady since January, his unfavorable rating has climbed by 12 points," said Murray.

Obama has a 59%-29% approval rating, but 76% of voters say their vote for governor "will be based solely on state and local issues." Just 6% of voters say they would switch their vote in the gubernatorial race if things "were going differently in Washington."  This group is "about twice as likely to be Christie voters as Corzine voters."

"At this stage of the race, it would be hard to claim that New Jersey voters view this campaign as a referendum on the Obama administration.  Still, the president's presence here could change that.  The Corzine camp's task is to make sure he activates the right group of voters," said Murray.

But Murray says Obama's appearance will help Corzine with his Democratic base.

"Jon Corzine is not doing as well among Democrats as he would like at this point.  The Obama visit is meant to link the fortunes of these two men in the minds of voters who already have a high opinion of the president, but are unenthusiastic about their governor and might sit this race out," said Murray.