While speaking at a campaign rally Thursday in support of GOP presidential candidate Mitt Romney, Sen. John McCain (R-Ariz.) mistakenly professed his faith in President Barack Obama's ability to improve the economy.

"I am confident, with the leadership and the backing of the American people, President Obama will turn this country around," McCain said, as seen above in a video from Goose Creek Patch.

McCain -- who endorsed Romney on Wednesday just after the GOP hopeful won the Iowa Caucus by a razor-thin margin -- appeared at the rally in Charleston, S.C., along with fellow Romney supporter Gov. Nikki Haley (R-S.C.).

The crowd, as well as Haley and Romney, quickly realized McCain's error. Haley leaned in to correct McCain, grabbing his elbow.

"Excuse me, President Romney," McCain said.

The Obama-Romney mix-up wasn't the only awkward moment during McCain's appearance. According to BuzzFeed's Zeke Miller, McCain made a comment about Clemson University's "victories on the gridiron."

Clemson lost the Discover Orange Bowl to West Virginia University on Wednesday night. Miller later tweeted that McCain intended the line as a joke.