Hillary Clinton
Hillary ClintonReuters

Many have repeatedly praised the sheer brilliance of Obama's presidential campaign, but what not everyone realizes is that Obama is still campaigning, even though he does not stand to be re-elected himself.

Obama's third presidential campaign is for Democratic candidate Hillary Clinton.

Even though outgoing second-term presidents generally stay out of elections, Obama has played a significant role in Hillary's campaign. And even though Hillary talks about how her policy will be different than Obama's, many Americans feel she will continue his "legacy" and a Clinton presidency will just be "more of the same."

At a campaign event in North Carolina last week, Clinton endorsed both Michelle and Barack Obama, saying, "She pulled our economy out of the ditch it was in when he became president. He saved the auto industry, he cracked down on Wall Street, he has tackled healthcare, climate change, civil rights, and so much else." She spent five minutes praising Michelle Obama, ending with, "Seriously - is there anyone more inspiring than Michelle Obama?"

Both Obamas will join Hillary Clinton in Philadelphia on Monday night, for a last pre-election rally.

For her part, Clinton has stated she will defend Obama's policy and build on his signature programs, using his popularity to bolster her own campaign. She has also avoided criticizing Obama's policy decisions during her election campaign - even though it's clear she disagrees with him, and disagreed with him as early as her term as Secretary of State.

A recent survey showed Obama as the all-time favorite US president of 35% of Democrats, with JFK taking second place at 21% and Bill Clinton in third place with 20%.

NBC News contributed to this article.