DEARBORN, Mich. — Republican Mitt Romney formally entered the presidential race Tuesday morning, telling a crowd in Michigan that his experience in taking on impossible challenges, his belief in God, freedom and the American people make him the best choice to take over the White House in 2008.

"Innovation and transformation have been at the heart of America's success," Romney said at the Henry Ford Museum in Dearborn., Mich. "If there ever was a time when innovation and transformation were needed in government it is now."

The speech lasted under 20 minutes but hit on major campaign points of the war in Iraq, health care, education, marriage and family values.

"It is time to build a new American dream for all Americans," Romney said.

With Ronald Reagan and John F. Kennedy's presidential limousines and a roomful of historical cars on exhibit just a few feet from where Romney spoke, the combination of cars and politics not only brought Romney back to Michigan — he was born in Detroit — but honored his late father George.

George Romney grew up in Idaho and Utah, where he attended Latter-day Saints University High School in Salt Lake City and the University of Utah. He briefly ran for president in 1968 but dropped out of the race two weeks before the New Hampshire primary that year. He was the chairman of the American Motors Corp. from 1954 to 1962, before being elected Michigan's governor in 1963. He died in 1995.

"This place is not just about automobiles ... it is about innovation, innovation that transformed an industry, and gave Americans a way of life our grandparents could never have dreamed possible," Mitt Romney said, as he stood in front of a DC 3 airplane, a Ford Hybrid and a Rambler — the car his father helped popularize.

"The Rambler automobile he championed ... was the first American car designed and marketed for economy and mileage," Romney said. "He dubbed it a compact car, a car that would slay the gas-guzzling dinosaurs. It transformed the industry."

Transformation was the announcement's key word, with Romney relying on his Mr. Fix-it resume to illustrate his track record.

"Throughout my life, I have pursued innovation and transformation," Romney said. "It has taught me the vital lessons that come only from experience, from failures and successes, from the private, public and voluntary sectors, from small and large enterprise, from leading a state, from being in the arena, not just talking about it."

"Talk is easy, talk is cheap. It is doing that is hard. And it is only in doing that hope and dreams come to life," he said.