Though Mitt Romney has defended his business record against attacks, there is a part of his past that he's more reluctant to discuss -- his time as Massachusetts' governor.

The presumptive GOP presidential candidate continually faced trouble over stances he took as governor of the Bay State, particularly on health care and abortion. Despite Romney's hesitation, Deval Patrick -- the current Democratic governor of Massachusetts -- told Politico Romney's work with health care reform was "profoundly important" to the states' residents.

“He did one profoundly important thing, and nobody can take it away from him, and that’s health care reform -- and he doesn’t want to talk about that,” added Patrick, who is close to Obama. “The impression he left with people here was he was more interested in having the job [of governor] than doing the job.”

In the past, Romney has avoided the topic of health care, putting more emphasis on his time at Bain Capital. Lately, he's even refused to partake in a full discussion on his business career thanks to new attacks by the Obama campaign.

HuffPost's Jon Ward reports:

But another reason may be that once Romney gets beyond the general argument that his time in the private sector better qualifies him to revive the economy, getting specific often means talking about the way the free market works. And that can be a politically difficult topic.

It's not as if Romney doesn't believe in capitalism. He devoted a full six pages in his 2010 book, "No Apology," to describing the merits of "creative destruction."

"It takes a leap of faith for governments to stand aside and allow the creative destruction inherent in a free economy, but it's a leap that has been successfully made by every advanced economy in the world," Romney wrote.

But even in that book, Romney made clear he knows that the idea of allowing businesses to fail, in the belief that a vibrant, innovative economy will produce new companies and more new jobs, can be a challenging argument to sell.

"Unions as well often oppose productivity innovations that will lead to reduced employment; understandably, they aren't persuaded by arguments that workers will eventually find employment in new enterprises," he wrote.

He also noted that the process can "unquestionably stressful -- on workers, managers, owners, bankers, suppliers, customers, and the communities that surround the affected businesses."

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