To use President Obama's words, Abraham Lincoln was "in the house" at a campaign event in Cedar Rapids, Iowa, on Tuesday.
Mr. Obama singled out an audience member dressed as Lincoln as "my homeboy from Illinois." He also called the former president's stand-in, "an outstanding Republican endorsee."
The two shook hands on a ropeline afterwards.
In the same speech, Mr. Obama said 2012 will be his last political campaign, "no matter what."
"I've got nothing else to run for," he told supporters.