As the Republican candidates ready for the debate in Orlando tonight, a Quinnipiac poll reports some gloomy news for Obama in Florida:

In 2008, then-Senator Barack Obama won Florida’s presidential election by winning over the state’s independent voters. Exit polls show 52 percent of them voted for Obama. That was then, this is now – and recent polls show that important voting bloc is cooling to the president.

According to the latest Quinnipiac poll, just 33 percent of Florida’s independent voters approve of the job the president is doing. A whopping 61 percent disapprove of his performance. …

Given the make up of Florida’s electorate, independent voters will make all the difference. Democrats make up 41 percent of the state’s registered voters, Republicans account for 36 percent. Nearly a quarter of Florida’s voters have elected not to register with either party.

To win in Florida, Obama will have to win 50 percent of independent voters, reports the St. Petersburg Times. Even a small drop in support could signal trouble, as he only carried independent voters by 52 percent in 2008. And what Quinnipiac found was definitely more than a small drop.

A related problem for Obama: Florida tends to be a microcosm of the nation when it comes to presidential politics. The state has voted with the national winner in every election since 1996 (and before 1992, it voted with the winner in every election since 1976). And the independent voters cooling to Obama in Florida are mirroring the national trend, as we can see from yesterday’s McClatchy-Marist poll, which found independent voters say they won’t support the president in 2012—53 percent to 28 percent.