New polling suggests that New Jersey Gov. Jon Corzine faces a difficult challenge for re-election this year. A Monmouth University poll released last week shows that just 34% of Garden State voters approve of the job Corzine is doing, compared to 51% who disapprove. Another recent survey shows that Republican Chris Christie, who as the state's hard-charging U.S. attorney has pursued a number of high-profile corruption cases, is leading the Democrat 44% to 38%.

In Virginia, the only other state holding a gubernatorial election this year, Democrats face an uphill battle against former state Attorney General Bob McDonnell. A Rasmussen survey conducted on Feb. 4 had McDonnell leading each of his three potential rivals, state Sen. Creigh Deeds, former state Delegate Brian Moran and former DNC Chairman Terry McAuliffe. None is as well known statewide as McDonnell, who will watch from the sidelines until the Democratic primary on June 9.

Circumstances in both states could certainly change by November. But more than the strength of Republican candidates, there's a unique historical pattern that should have Democrats concerned. Since 1989, the party that has controlled the White House has lost gubernatorial elections in each state.

That year, George H.W. Bush's first as president, New Jersey's Jim Florio and Virginia's Doug Wilder won their respective races. Republicans took back the offices in the two following elections, as Democrat Bill Clinton served in the White House. But the pendulum swung again in 2001 and 2005, when George W. Bush served as president.

Strategists in both national parties typically pay additional attention to these contests every four years. With only a handful of elections scheduled in the "off-year," these two key gubernatorial contests are often spun as a measure of the parties' strength heading into midterm election years.

Control of the state offices is considered an even greater priority in the coming years because of the role governors will play in shaping redistricting decisions after the 2010 census.

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