The Democrats swooned at his fresh-faced optimism and within a matter of years Mr Obama led the party to the presidency.
Fast forward to 2018 and some see history repeating itself.
Democrat Beto O'Rourke, a congressman from El Paso, Texas, is taking on conservative firebrand Ted Cruz for the state's Senate seat in the US midterm elections on 6 November.
The 46-year-old is a married father of three with a punk rock past; he played bass in an early '90s band called Foss, which toured both the US and Canada. And he's still partial to a bit of skateboarding.
Unabashedly progressive, Mr O'Rourke has spent his campaign espousing health care for all, criminal justice reform and stronger gun safety laws.
He gained national and even international prominence in August after a video of him went viral. In it, he vocally supports American football players who decided to "take a knee" during the US national anthem to protest against racism.
Mr O'Rourke has since gained a cult following and raised an eye-popping US$70 million.
According to the Washington Post, his fundraising haul has exceeded the amounts raised by 2016 top presidential candidates such as former Florida governor Jeb Bush, Senator Marco Rubio of Florida and then-New Jersey Govenor Chris Christie.
He's amassed 700,000 followers on Twitter and earned celebrity endorsements; nearly 60,000 people turned up at a September rally to watch Mr O'Rourke and Willie Nelson play guitar together.
Republicans released an apparent mugshot of the congressman from a mid-90s arrest, but the move backfired with thousands of fans jumping to his defence on social media.
US outlet Politico has termed the phenomenon "Beto-mania".
Over recent months, the candidate's ability to pull both crowds and money, along with his oratory and policy points, has seen several comparisons made to Mr Obama.
For Dougal Robinson, a non-resident fellow at the University of Sydney's United States Studies Centre, there's a clear similarity.
His "optimistic message of 'change' is not dissimilar to Barack Obama," Mr Robinson told SBS News from Washington DC.
Cable news networks CNN and Fox News have both talked about the "national excitement" on the left around Mr O'Rourke not seen since the Obama days.
President Trump won Texas by nine points in 2016 and the state has not elected a Democrat to the Senate since 1988, but as one recent Vanity Fair article read:
"[Democrats] look uneasily at the current crop of potential candidates, and keep waiting for their Obama-like saviour to surface. The thing is, it might be happening right now in Texas."
Counting 254 counties
Mr O'Rourke has made the point of campaigning in all 254 Texas counties - some of which went 85 per cent to Mr Trump over Hillary Clinton.
At rallies, he has talked about an unfair justice system that targets minorities, getting corporate money out of politics, legalising marijuana and how Mr Trump's border policies have kept hundreds of detained immigrant children separated from their parents.
"This is a campaign for the future, because the people of the future - our kids and our grandkids - are depending on what we do at this moment. Let tonight be a message to the future," Mr O'Rourke said at a September rally.
"Whoever you pray to, whether you pray at all, whoever you love, however many generations you've been in this country or whether you just got here yesterday, we're all in the same boat, we're all human beings, and we're going to start treating one another that way."
'Socialist to the core'
But not everyone in Texas has been swept up by "Beto-mania".
Mr O'Rourke is "very intelligent and he's a good speaker, but he's liberal as hell," real estate executive James Griffith told AFP in September, as he attended the West Texas Fair & Rodeo in Abilene.
Winston Ohlhausen, a local who was also attending the event, said "he's socialist to the core," claiming the Democrat does not share "Texas values".
"He's for sanctuary cities, no border wall, he's for more taxes, for abortion ... I think Cruz is going to wipe him out bad."
And while Mr O'Rourke pulled close to Mr Cruz in the polls last month, he's now trailing the Republican by an average of seven points as the midterm elections near.
"Despite O'Rourke's popularity, it remains unlikely that he will win this year, or Democrats will win Texas in the presidential race in 2020. But it is clear that a ruby red state is becoming more and more contested," Mr Robinson said.
"[And] his relative success in the campaign has forced Republicans to use money and time to defend Ted Cruz in a historically red state, taking resources away from other states and therefore helping fellow Democratic candidates."
Mr Trump visited the state to attend a rally for Mr Cruz last month, a sign that Republicans have a degree of concern around the result.
"He defended your jobs. He defended your border ... He defends your families and your faith," Mr Trump said.
"We are defending together with other great Republicans your freedom," he said, encouraging Texans to "get out there and vote."
The president also tweeted that Mr O'Rourke is "a flake" who "wants higher taxes and far more regulations".
Whatever the result for the Texas Senate seat on Tuesday, it likely won't be the last we hear about Beto O'Rourke.
As Vanity Fair puts it, "on what planet is Beto O'Rourke not a presidential contender, even if he loses?"
Additional reporting: AFP