"Please help me defeat Barack Obama next November," he asked an energetic crowd in Broomall, a suburb of vote-rich Philadelphia. "We just got to get him out of office. He just doesn't understand what's happening to the country.
The event, Romney's first in Pennsylvania ahead of the April 24 primary, had a boisterous feel as the Republican frontrunner basked in the glow of his three primary wins the previous night in Wisconsin, Maryland and the District of Columbia.
Supporters rewarded the rote lines in his stump speech - promises to lower taxes and cut regulations combined with sharp attacks against President Obama's management of the economy - with hearty applause that sometimes drowned out his words.
But as much as Romney wanted to pivot to the general election, especially in a state that will be a key battleground in November, he could not escape the nagging reality that his trip to the Keystone State was fundamentally about Rick Santorum, not the president.
"On April 24, I need you to take the next step," Romney told the crowd, asking for their votes in the upcoming Republican primary.
Romney did not mention his Republican opponent in his remarks, but he is spending two days here with clear designs on vanquishing Santorum in his home state, hoping to undercut his rival's candidacy once and for all.
On Thursday, Romney departs the Philadelphia area, where he's likely to perform well in the affluent suburbs, and will venture into the central part of the state to campaign in Harrisburg and Scranton, two locales where Santorum may have an advantage.
A recent poll showed Santorum barely leading Romney in Pennsylvania, one of five northeastern states holding primaries later this month.
Several Republicans who attended the rally said they were excited to get on with the general election fight and finally put months of Republican infighting behind them.
"Santorum is just not presidential material," said Micki DiBella Pirrotta, a property manager who was laid off from her job last year. "I can't wait to vote against him."
But Bill Smith, a Republican who works as a foreman at a welding facility, said Romney still has to prove that he cares about the middle class and working Americans instead of wealthier people.
"The man has to touch base more with middle America and lower America," Smith told CNN. "He needs to not just speak about it, he has to live it. He is from upper America. He pays a lower tax rate than I do. But he is a businessman and maybe that would be good for us."