Businessman and radio talk show host Herman Cain formalized his expected 2012 presidential bid Saturday at a rally in his hometown of Atlanta.

Cain, the former CEO of Godfather’s Pizza, introduced himself as the son of a chauffeur and a domestic worker who was living the American dream.

“I’m running for president of the United States and I’m not running for second,” he told the crowd.

In a spirited speech, Cain criticized President Barack Obama on several fronts. He said Obama threw Israel “under the bus” during a speech on the Middle East this week. He also disparaged the president’s efforts to stimulate the economy and the administration’s move to sue Arizona over the state’s controversial immigration law.

Cain is viewed a long-shot candidate in the White House race, although some believe he could emerge as a legitimate competitor in a field that lacks a strong frontrunner.

Former Minnesota Gov. Tim Pawlenty is expected to launch his presidential bid on Monday in Iowa. The GOP field currently includes former Speaker Newt Gingrich (Ga.) and Rep. Ron Paul (Texas). Former Massachusetts Gov. Mitt Romney, considered the nominal frontrunner by many at this point, is also expected to run, as is Rep. Michele Bachmann (Minn.) and former Utah Gov. Jon Huntsman. Indiana Gov. Mitch Daniels is also contemplating a bid.

Cain’s previous foray into politics was a failed 2004 Senate bid in Georgia. He lost the GOP primary to now-Sen. Johnny Isakson, who said this week that he is not making an endorsement in the 2012 White House contest.