President Barack Obama, long fiercely defended by Democrats and demonized by Republicans, is on pace to be the most polarizing president in American history, according to Gallup. But that may not be all his fault; it could be a sign of the times.

During Obama's fifth year in office, 82 percent of Democrats and just 11 percent of Republicans approved of the job he was doing, marking a 71 percent partisan gap, according to a Gallup polling analysis released Thursday. That's the fourth most polarizing year in Gallup's records, but down from the 76 percent gap during his fourth year – also his re-election year – which is typically a president's most polarizing.

But Jeffrey Jones, a polling analyst with Gallup, said the hyper-polarization trend started not with Obama, but with his predecessor, former President George W. Bush.

"Obama is on course to have the most politically polarized approval ratings of any president, with an average 69-point gap during his presidency, a full eight points higher than was the case with Bush," he said in a memo accompanying the polling analysis. "Each year since 2004, the average party gap in presidential job approval has been 60 percentage points or greater. The only other two years with that degree of polarization were Ronald Reagan's and Bill Clinton's re-election years."

The partisan gap was magnified for Bush and Obama thanks to a lack of support from the opposition party, rather than trouble garnering support from their own respective parties.

During their fifth years in office, Bush's approval rating among Democrats was 14 percent and Obama's approval rating among Republicans was 11 percent, according to Gallup. Reagan, Clinton and former President Dwight Eisenhower received at least 30 percent approval from their opposition party during the same period in their presidencies.

"Obama's highly polarized ratings, then, may have as much to do with the era in which he is governing as they do with his actions as president," Jeffries said. "Both Obama and Bush made overtures toward bringing politically divided Americans together, but the evidence suggests neither succeeded. That said, it is not clear that presidents will be very successful in gaining significant support from the opposition party, regardless of what they do in the current political environment."

Gallup analyzed more than 175,000 daily tracking interviews conducted throughout Obama's fifth year in office, from Jan. 20, 2013, through Jan. 19, 2014, to come up with these results.