The most competitive states for gubernatorial elections

High-profile races for governor are under way in Pennsylvania and New Jersey.

In the Garden State, Republican Gov. Chris Christie is expected to face off against State Sen. Barbara Buono this fall. And in Pennsylvania, Democrats are already exploring runs against Gov. Tom Corbett, whose popularity has been slumping in recent polls.

So just how close are those races likely to be?

According to the University of Minnesota's Smart Politics site, New Jersey's gubernatorial elections are the eighth-most-competitive in the country, with an average margin of victory of 10.5 percent since 1900. Pennsylvania ranks 15th, with an average victory margin of 11.9 percent.

Here are the average margins of victory for the top 15 states; check out Smart Politics for the full list.

1. New Mexico, 7.5 percent

2. Indiana, 9.3 percent

3. Ohio, 9.8 percent

4. Alaska, 9.9 percent

5. Missouri, 10.2 percent

5. Connecticut, 10.2 percent

7. Illinois, 10.3 percent

8. New Jersey, 10.5 percent

9. Hawaii, 11 percent

9. West Virginia, 11 percent

11. Washington, 11.2 percent

12. Massachusetts, 11.3 percent

13. New York, 11.6 percent

14. Montanta, 11.8 percent

15. Pennsylvania, 11.9 percent