He directed his barbs instead at the president, while his staff urged supporters in this generally Republican and generally well-heeled section of Philadelphia's suburbs to divert their contributions to a November-focused "Romney Victory" fund.
Santorum, meanwhile, was 108 miles west, greeting supporters at a bowling alley outside Harrisburg and scrambling in anticipation of what he called a "must-win" primary in his home state. He did so even as the ultimate party elder - former GOP presidential nominee John McCain - called on him to make a "graceful exit" from the race.
"We still have a long way to go," Santorum said at the campaign stop in Mechanicsburg.
With the scene set for Pennsylvania's three-week Republican primary fight, both candidates were generally sticking with what they do best.
For Romney, a former management consultant, that meant emphasizing his business bona fides before a crowd of Republicans at the Iron Shop, a family-owned spiral-staircase manufacturing company in Broomall - and attacking the president, whose name was greeted with a chorus of boos.
For Santorum, it meant hopscotching the western and central parts of the state he once represented in the Senate, jumping from one blue-collar setting to another - including stops at a Pittsburgh-area diner and a few frames of bowling at the alley in Mechanicsburg.
Expect much of the same over the next three weeks.
But for either candidate to take a commanding lead in Pennsylvania before April 24, each needs a little of what the other one already has, Republican analysts say.
Just over a month ago, a poll gave Santorum that kind of lead - an edge of nearly 30 percentage points over Romney. That has since dwindled to fewer than 10 points, according to recent surveys by pollsters at Quinnipiac University, and Mercyhurst and Franklin and Marshall Colleges.
All through his 11 primary and caucus victories to date, Santorum has done best with rural and blue-collar voters, and evangelical Christians - who make up the majority of Republicans in Northern and Central Pennsylvania. And if his visit to Mechanicsburg on Wednesday night was any indication, he's likely to clean up in those regions.
Flanked by four of his children, Santorum strapped on a pair of bowling shoes and donned a custom jersey embroidered with his name before tossing the pins around. His bowling drew cheers from the hundreds gathered.
Among them: Luke Lawley, 32, a waiter from Enola, Pa. "He has good values. He's a family man. He's honest," Lawley said. "He's the closest thing to an ideal candidate."
The campaign stop was expected to be the former senator's last this week - he is planning to take the Easter holiday off.
Meanwhile, Romney's entourage, too, was wending its way across friendly territory - Philadelphia's vote-rich suburbs, where his appeal to more fiscally minded, moderate Republicans has sat well with most local GOP leaders.
That his first public rally in the state in more than nine months was at the Iron Shop was no accident, said Delaware County's Republican committee chairman, Andrew J. Reilly.
Romney made another visit more than a year ago to the staircase company in the heart of a county with one of the nation's most reliable Republican machines. Back then, Romney was just launching his second bid for the presidency.
On Wednesday, with sleeves rolled up and shirt collar unbuttoned, he spoke as if he had already eliminated Santorum as an obstacle in his way.
"The president says he wants to transform America," Romney said. "He's crushing dreams, he's crushing the dreamers, he's crushing the middle class."
Not once did he mention Santorum, while lambasting Obama on everything from the president's health-care initiative to his handling of the economic recovery.
Campaign staffers flitted among the crowd urging supporters to begin writing checks to a finance supporting anti-Obama efforts, a joint venture between Romney's campaign and the Republican National Committee.
Democrats, too, fed the air of Romney inevitability by flooding Philadelphia and its surrounding suburban counties with grassroots organizers and Obama surrogates unwilling to cede the spotlight to the GOP.
"If there was a poll tomorrow that said Americans wanted a Rastafarian for president, Mitt Romney would have dreadlocks by the end of the day," said state Sen. Daylin Leach (D., Montgomery), referring to frequent criticism that the former governor has changed positions. Again, no mention of Santorum.
Leach spoke at a media conference in Havertown - one of several events featuring party leaders, including Democratic national chairwoman Debbie Wasserman Schultz, U.S. Rep. Allyson Y. Schwartz (D., Montgomery), and Bill Hyers, the Obama campaign's state director, planned in the Philadelphia area this week in response to the Republicans' arrival.
For Santorum, who lost his last statewide election here in a 2006 landslide, returning home offered the possibility of a redemption in the face of rising pressure from GOP leaders, now including 2008 nominee McCain, to bow out of the race.
McCain said on CBS This Morning that Santorum should recognize "it's time for a graceful exit" from the Republican campaign in the wake of Romney's sweep in Wisconsin, Maryland, and the District of Columbia.
In Mechanicsburg, Santorum, instead, reminded listeners of the excitement deficit that has plagued Romney's candidacy and has worried GOP strategists throughout much of the primary season.
"Folks want someone they can get excited about, who they can trust, and who can beat Barack Obama," he said. "The question is, why isn't [Romney] blowing the doors off this thing?"
Contact Jeremy Roebuck
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