Gerald Herbert/AP Photo

MONROE, Mich. - Mitt Romney, in his continuing bid to attract Michigan voters and differentiate himself from the other GOP candidates, said today that while working as a "lobbyist" or an "elected official is great," his own private-sector experience trumps all.

"I understand jobs because I've had jobs. I mean, I look at our president, and frankly others who are running in this race who have never worked in the private sector," said Romney, who did not mention former House Speaker Newt Gingrich or former Sen. Rick Santorum of Pennsylvania by name. "Working as a lobbyist and working as an elected official is great, but in my view, it's more important to also have private-sector experience to get this economy going.

"And, as you know, I've had that experience," he added.

Romney and his campaign have spent weeks lobbing insults at Gingrich for his work at mortgage giant Freddie Mac, a tenure Romney has said makes the former congressman a lobbyist. Similarly, the Romney campaign has recently focused on Santorum's voting record during his time in the Senate.

Speaking at a roundtable at steel manufacturer National Galvanizing, Romney said his private-sector "mindset" is key to balancing the budget and bringing change to Washington.

"I want to underscore how important it is to have people go to Washington to fix Washington, and don't go there and get fixed by Washington," Romney, 64, said.

"It can be done but it's going to require leadership, and I do believe it's going to require someone coming from outside Washington," Romney said of balancing the budget. "I mean, you describe the leadership here in the state, all of you have extensive experience in the private sector. I think there is a mindset as well as a skill that comes from having worked in the private sector, where you've got to balance budgets or you'll go out of business."

Romney also continued to criticize President Obama for engaging in what he calls "crony capitalism."

"Look, unions play an important role in our economy," Romney said. "But I believe union and nonunion shops should compete on a level playing field. I don't believe the president should step in and say, 'Well, we're going to have a regulation here that says all federal work has to be done by unions. And, so I say, number one, we're to make it a level playing field."

"Number two, we're going to have right to work, where individuals or workers can choose whether they want to be a member of a union or not," he said. "Number three, we're not going to tell union members we're taking dues out of your paycheck to go to a political action committee you may disagree with. That's simply wrong.

"Let's make sure we don't have crony capitalism where a president is giving to his friends that helped him in his campaign, in this case the unions."