PRESIDENT BARACK OBAMA appears to have the upper hand in the crucial swing state of Ohio, according to early exit polls, while the president will also be encouraged by early polling data coming in from Florida.

An exit poll commissioned by CNN said that while Ohio – which has 18 votes – is too close to call, but suggested the Democratic candidate held a 51-48 lead in the race to secure the precious votes.

Ohio is considered a key bellweather state which would be vital to Mitt Romney if the Republican hopes to reach the magic 270 needed to oust Obama; no Republican has won the White House without the support of Ohio voters since 1928.

Meanwhile, with over a quarter of the votes counted in Florida, Obama leads by the same margin – 51 to 48 – with results showing that the president has improved upon the narrow lead he built up in that state in 2008.

Polls in Florida do not fully close until 1am Irish time, but some eastern parts of the state closed at midnight Irish time with votes already being counted.

Live results: US Election 2012