STEPHANOPOULOS: And for more on this, we now turn to one of the men looking to replace President Obama. Former Massachusetts Governor Mitt Romney came in second to John McCain for the Republican nomination back in 2008. He's the next guest in our series "Vote 2012: The Challengers" Mr. Romney has also written the bestseller No Apology, Believe in America, which is now out in paperback. Thanks for coming in this morning.

MITT ROMNEY: Thanks, George. Good to be with you.

STEPHANOPOULOS: So, if you were in the Oval Office right now would you tell President Mubarak go?

ROMNEY: Well, I think what the United States has to do is make it very clear to the people of Egypt that we stand with the voices of democracy and freedom. And we also have to communicate, and I think this administration has, that we would like to see a transition to a permanent democracy, not just a one-time, one-vote and then the extremists take over, but, instead, a permanent democracy with the rule of law, with the support for the allies that have existed in the past. And that kind of transition, I think, would be best undertaken if President Mubarak would step out of the way or lead the transition. But, I don't know I would say to the president you should call for Mubarak's resignation. That, I think flies in the face long history of friendship between he and our country and our friends. But it's very clear that he needs to move on and to transition to the voices of democracy.

STEPHANOPOULOS: So, it sounds like you have no quarrels with how the administration is handling this so far?

ROMNEY: Well, I think they got off to a rocky start. I think some of the statements early statements were misguided. But, I think hey corrected and said they want to see transition, I think that's right and I think you're going to find Mr. Wisner and others will say, look there ought to be a transition that you Mr. Mubarak or someone else leads to voice of democracy on the street. We are a nation who demands freedom, free enterprise, democracy, right course for Egypt. That's the right course.

STEPHANOPOULOS: Let's turn now to health care. Major court ruling. Federal judge down in Florida targeted individual mandates, said that the President Obama health care reform is unconstitutional and in doing that, he wrote this: He said "It is difficult to imagine that a nation which began as result of opposition to a British mandate giving the East India company a monopoly and imposing a nominal tax on all tea sold in America would have set out to create a government with power to force people to buy tea in the first place." Do you agree with that?

ROMNEY: I absolutely do. I think it is a very bad piece of legislation. I think the President should have been more attuned to what we did in our own state, which is we allowed each state to create a solution to the issue of the uninsured in the way states thought best, that's the way the Constitution intended it. We're a federalist system. We don't need the federal government imposing a one-size-fits-all plan on the entire nation.

STEPHANOPOULOS: But, what he was talking about, specifically, was this requirement that people buy health insurance and you had exactly that same requirement in Massachusetts. Why is it right for a state to impose that kind of mandate and not the federal government?

ROMNEY: Well, states have rights that he federal government doesn't have. Under the 10th amendment of the Constitution, the powers of the federal government are specifically limited. The states have the right to, for instance, mandate kids going to school, mandate auto insurance. States have certain rights they can exercise, try different things this different states, find out what works and what doesn't. But, the last thing you want to see is the federal government usurping the power of states. This is a federalist nation. It's unconstitutional. By, the way, it's also bad policy. What works in one state is not going to work somewhere else. And I'll be the first to tell you as well, our plan isn't working perfectly. There are a number of things I would do differently the second time around and the right thing for the President to do now with these decisions saying his bill is unconstitutional, with the House taking action to repeal it, with the Senate considering doing so, he should press the pause button and say let's hold back on this Obamacare.

STEPHANOPOULOS: But, I'm interested in the distinction you're drawing, which is a valid distinction. But it's not- it's not going far enough for many Republicans, as you know. Even Karl Rove, President Bush's former advisor, has said that unless you find a way- that the number one challenge to you getting the nomination in the Republican Party is your support for this individual mandate. And you have got to find some way to work around it but you're sticking by the title of your book, No Apology. You not going to apologize for the individual mandate?

ROMNEY: Well, I certainly indicating that there's things I would do differently and I point that out in the book. But, I'm not-

STEPHANOPOULOS: Is that one of them?

ROMNEY:  I'm not going to apologize for the rights of state to craft plans in a bipartisan basis they think will help their people. But, I can tell you, which is, the politics of it are something I'm not going to give a lot of worry to. I'm going to focus instead on the things I believe.

STEPHANOPOULOS: So, let me be specific: Are you apologizing for imposing that requirement that people buy health insurance?

ROMNEY: Of course not. Of course I'm not apologizing for it, I'm indicating that we went in one direction and there are other possible directions. I like to see states pursue their own ideas, see which ideas work best. That was the whole idea of our federal democracy. We have people able to try different ideas, state to state but what we did not do was say that the federal government could make its choice and impose that on all of the states. That's one reason this bill is unconstitutional.

STEPHANOPOULOS: So, you're leading the Republican pack in fund-raising right now, even though you haven't made a final decision to run. Is there anything that can stop you from take on President Obama?

ROMNEY: Well, I haven't made a decision yet as to what we're going to do. That decision will be made down the road. But I can tell that you that I'm very drawn to the fact that this country needs someone who has private sector experience because this economy is troubled. We've got a President who says a lot of the right things but doesn't know how to get the job done. Almost everything he has done in his first two years has made it more difficult for our economy to grow. It's been the most anti-investment, anti-job, anti-growth administration we've seen in a long time. And so, I'm inclined to make sure there is somebody in the race who understand how the economy works and get jobs back.

STEPHANOPOULOS: So, I noticed one change from the last campaign already. You're here this morning with no tie.

ROMNEY: Hey, I'm not a candidate. I'm just having fun.

STEPHANOPOULOS: Well, what else did you learn from the last run?  What mistake won't you make the second time around if you run?

ROMNEY: Well, I'm sure I'll avoid some mistakes last time but I'll make new ones this time. Probably first and foremost is to make sure your message gets through, that you don't get diverted by all of the daily events that occur and speak on every possible topic but instead you focus on what you care about. In my case, getting America working get, getting our economy strong to protect yourself globally. We can provide freedom for ourselves and our friends and have a more prosperous future for ourselves and our kids.

STEPHANOPOULOS: Okay, Governor Romney. Thanks for coming in this morning. Hope you come back when you're an official candidate.

ROMNEY: Thanks, George.

STEPHANOPOULOS: And you can read a chapter from No Apology at ABCNews.com/GMA.