If unemployment rates are the most important factor in 2012 politics, then President Obama got some good news today.

Unemployment rates dropped in 45 states and rose in one (New York) in the last year, according to new, preliminary data released Tuesday by the Bureau of Labor Statistics. BLS compared preliminary state-specific rates calculated for January 2012 to finalized rates from January 2011.

The latest nonfarm, seasonally adjusted national unemployment rate is 8.3 percent for February, unchanged from January, BLS announced on Friday.

Some of the biggest improvements came in beleaguered swing states expected to weigh heavily in the 2012 presidential race-states where higher-than-average jobless rates could threaten Obama's reelection prospects.

Ohio, which clenched Obama's victory on Election Night in 2008, saw its rate drop 1.3 percent, from 9 percent to 7.7 percent. In Colorado, which Obama won by 9 percentage points in 2008, the unemployment rate fell 1 percent, from 8.8 percent to 7.8 percent.

Michigan suffered one of the nation's highest unemployment rates at 10.9 percent in January 2011-but that number has since dropped 1.9 percent to 9 percent, BLS reported. Obama carried Michigan by 16 percentage points in 2008, but should Mitt Romney win the GOP nomination, his home state could become competitive in a bad economic climate.

Florida's rate dropped 1.3 percent, from the same 10.9 percent in January 2011 to 9.3 percent in January 2012. With 27 Electoral College votes, the Sunshine State will be important for Obama in the fall. "We can't just have a Florida strategy, but Florida's the easiest way to 270 electoral votes," Obama for America Campaign Manager Jim Messina said in laying out the president's various paths to victory in a December YouTube presentation, insinuating that a win in Florida could make up for losses in a handful of swing states.

Some of these rates are still much higher than the national average, and their continued improvements would pose a question in the 2012 campaign: What will determine Obama's standing, the actual rates or their trajectory? As ABC Polling Director Gary Langer has pointed out, both are important to consider.