He accused the senator of pessimism, outlining a $20 billion industry recovery package and telling audiences in economically ailing Michigan, "I will fight for every single job."
Romney also tweaked his stump speech to criticize McCain for stating that he was more familiar with foreign affairs and military matters than economic issues.
Highlighting his 25-year business career, he told audiences, "Senator McCain says the economy is not his strong suit; well, it is my strong suit."
As the calendar progressed, however, McCain picked up a big-ticket win in the Jan. 19 South Carolina primary. Romney instead focused on his victory in the Nevada caucuses the same day.
Ten days later, the two squared off again in the Florida primary, where McCain scored a major upset after winning endorsements from the state's two top elected Republicans — Gov. Charlie Crist, a popular figure who had previously said he planned to remain neutral in the race, and Sen. Mel Martinez.
The following day, Giuliani dropped out of the race and endorsed McCain. A day later, popular California Gov. Arnold Schwarzeneger announced his endorsement of McCain, reflecting a coalescing of Republican support behind the senator as he approached a Super Tuesday showdown with Romney.
Romney's final pitch was to label McCain a liberal like Clinton and Obama, a charge tantamount to heresy in the GOP. He was backed by conservative media voices like Rush Limbaugh and Ann Coulter.