Obama's approval rating is at its highest point in years, and that could be a big problem for Donald Trump

President Barack Obama
President Barack Obama

(President Barack Obama laughs at a joke told by Prime Minister Lee Hsien Loong's toast of the president during a state dinner, Tuesday, Aug. 2, 2016, in Washington.AP Photo/Jacquelyn Martin)

Barack Obama strode to the stage at last month's Democratic National Convention in an unusual speaking slot.

He spoke in the primetime hour Wednesday night, a spot typically reserved for a vice-presidential nominee.

In 2000, for instance, former President Bill Clinton spoke on Monday night of then-Democratic nominee Al Gore's convention. Former President George W. Bush, deeply unpopular in his second term, didn't show up for then-Republican nominee John McCain's party in 2008.

Obama's speaking slot was by design. It previewed an outsize role in his final campaign: Electing Hillary Clinton to be his successor in the White House.

"President Obama gives Hillary Clinton a hat trick: He can help unite the party by bringing out Bernie Sanders supporters into her camp, deliver an aggressive contrast about the threat posed by Donald Trump, and ensure that all the supporters of the Obama coalition show up in November," Ben LaBolt, a former spokesman for Obama's presidential campaigns, told Business Insider earlier this year.

Obama is prepared to campaign for his party's presidential nominee more than any sitting president in recent history. That could be a big problem for the GOP and its nominee, Donald Trump. And a huge boon for Clinton.

The president's approval rating got its own convention bump: In a CNN/ORC poll conducted after the convention, 54% of Americans said they approved of Obama's job performance. It was his highest mark since right before his second inauguration in 2013. Just 45% disapproved.

That number is significant. Earlier this year, an NBC/Wall Street Journal poll found that President Barack Obama's approval rating had jumped to 51% — its highest point since his second inauguration.

NBC's team of political analysts called it the "most important number" out of the poll.

"Why is it important? Because it means that Obama will be an asset to Hillary Clinton on the campaign trail unlike he was in the 2014 midterms, when his approval rating was in the low 40s," NBC's Chuck Todd, Mark Murray, and Carrie Dann wrote.

The threshold might seem arbitrary. But historical precedent suggests it could bode well for Clinton, Obama's former secretary of state.

Early this year, Obama's approval rating hit 50% in the weekly average from Gallup's daily survey. As of Friday, it stands at 51%. For Obama, whose approval ratings have been stuck in the mid- to low-40% range for much of his second term, it was a notable bump.