The Los Angeles Times reported earlier this month that four of the 10 top dollar investments by Bain under Romney's leadership went bankrupt.
Downside Of Reality
"It's the downside, it's the reality of what life is like in the private sector," Romney responded when asked about that success rate.
Testing an argument he might make in a general election, Romney pointed to the federal government's bailout of the auto industry, which included dismissals.
Obama "wanted to save the enterprise," Romney said. "A profit in enterprise is essential to keep it alive and to keep people employed."
The auto bailouts saved more than a million jobs, according to the Obama administration and Democrats.
Romney also kept up his criticism of Newt Gingrich, who has surged in state and national polls of the Republican contest. He specifically cited the former U.S. House speaker's comments in May about a House Republican entitlements plan that was put forward by Budget Committee Chairman Paul Ryan.
"The speaker said this is right wing social engineering," Romney said. "He cut the legs out from a very important message."
Romney called Gingrich an "unreliable" conservative who sometimes has "zany" ideas. "I would not think you'd call mirrors in space to light highways at night particularly practical," Romney said.
Long Nomination Fight
Romney said he is prepared for a long nomination fight if there is no clear victor after the first four contests in Iowa, New Hampshire, South Carolina and Florida. The voting starts Jan. 3 with the Iowa caucuses.