UPDATE: Mitt Romney: 'No One Has Ever Asked to See My Birth Certificate'

COMMERCE — An eager, happy crowd which reportedly swelled to 9,300 greeted presidential candidate Mitt Romney during his first trip back to Michigan since selecting  as his running mate.

However, a joke Romney made about his roots in Michigan made the biggest headlines from the visit.

A three-hour event at Long Family Orchard in Commerce was "rocking and rolling" from the moment doors opened at 9:30 a.m., through 85 degree-heat and steady sun which caused a few in the audience to require medical attention.

Marked by speeches from Oakland County Commissioner Christine Long, who hosted the event with husband Rob; Michigan Lt. Gov. Brian Calley; and U.S. Senate hopeful Pete Hoekstra among others, the event seemed to serve as a rally for the entirety of conservatives in southeastern Michigan.

A crowd of about 50 protesters greeted Romney on Commerce Road as his tour bus pulled up amid . Romney acknowledged the protesters, who waved signs and chanted, "Four more years!"

"I saw someone with a sign that said four more years and I said, 'You want four more years of eight-percent unemployment? You want four more years of record numbers of foreclosures?'" Romney said.

Romney derided President Barack Obama's term in office after winning a first term in 2008, saying that while Obama "has tried," he hasn't been able to solve issues at the forefront of politics in Michigan.

In what was the first official visit to the Mitten State for vice presidential candidate Paul Ryan, a U.S. Representative from Wisconsin's 1st district, points of pride for the Midwest were made clear.

Ryan remarked, "Remember about four years ago when he was talking to a bunch of donors from San Francisco and he said people from states like ours like to cling to our guns and our religion? I just have one thing to say: this Catholic deer hunter is guilty as charged and proud of it."

Romney's wife, Ann, a graduate of Kingswood School in Bloomfield Hills, expressed her pleasure to be back in the area, while Mitt shared the story of how the two began courtship as a senior at Cranbrook in the mid-1960s.

Romney made a quip which drew a quick response from the Obama campaign referencing his own background in relation to the president's:

"Ann was born in Henry Ford Hospital. I was born in Harper Hospital. No one has ever asked to see my birth certificate. They know that this is the place that we were born and raised," Romney said.

The joke grew laughter and applause from the Michigan faithful, but the Obama campaign said afterwards that Romney had referenced the "birther" movement: a group of political opponents and conspiracy theorists which have put forth since the mid-2000s that Obama's birth certificate is a forgery, among other theories. 

"Throughout this campaign, Governor Romney has embraced the most strident voices in his party instead of standing up to them," wrote Obama campaign press secretary Ben LaBolt in a release to media Friday afternoon. "Governor Romney’s decision to directly enlist himself in the birther movement should give pause to any rational voter across America."

Among Romney's biggest talking points:

• Making America energy independent.
• Make sure people have the skills to succeed.
• Trade that works for America.
• Cutting deficit to zero.
• Championing small businesses.

The Republican National Convention is scheduled for Aug. 27-30 in Tampa.

Updated: 3:20 p.m., Friday, Aug. 24

More: