Who leads the GOP in 2016?

DW: Donald Trump, the leading Republican presidential candidate, wants to ban Muslims from entering the United States, while Ted Cruz, another leading Republican contender, has said the US should "carpet bomb" terrorists into oblivion to find out whether "sand can glow in the dark." When you hear statements like these, are you sometimes ashamed to be a Republican?

I am not ashamed. It makes my skin crawl. I don't agree with it. I think they are speaking for themselves and not for the kind of Republican Party I believe in. So it makes me sad right now that they are the leading contenders, because they are unfortunately defining the party and reaching out to what they consider their base and strengthening that. But I am not ashamed of the history of the Republican Party and that's what I look at.

So what has happened to the so-called Grand Old Party of Abraham Lincoln that it is being dominated by Donald Trump and Ted Cruz?

It is the kind of thing that is happening to the Democrats with Bernie Sanders. People are frustrated and angry and scared. And when people feel that their government is unproductive, which our government notoriously has been, they are looking for any kind of a leader who says this is what I am going to do and I am going do it. They also believe that this administration has engaged in an overreach of executive powers. You can argue they do that because Congress doesn't work, but that is still a legitimate argument that these people have. We want to see something done, and we want someone who says he can get it done and then damn the torpedoes and full steam ahead.

Isn't there a difference between Bernie Sanders and Donald Trump? Bernie Sanders certainly hasn't made xenophobic statements, and his rhetoric is very different than that of Trump.

No he hasn't. He is moving the Democratic Party to the left. We have been moving to the right longer as Republicans. So we are further along than they are. And we do it better. We make more outrageous statements.

Our problem starts with only 10 percent of the American people, eligible voters, voting in primaries. When that happens you are letting the most partisan, and they tend to be the more extreme and passionate people, make the decisions for you. And then the people in the middle end up with choices they don't like and they wonder why. So they decide they are not going to vote or they register to vote independent which is what happened. The growth of independent registered voters is far greater than that of either Republican or Democrat. So they are tapping into a frustration. And when people are scared, these tactics that Trump and Cruz are using - while deplorable, and they are deplorable – they are the ones we have seen used before by dictators around the world.

In fact, you have compared Trump's rabble-rousing rhetoric to that of Hitler and Mussolini. Do you really think such a stark historical comparison is justified?

I do. I am not saying that they are Hitler or Mussolini. They don't have a "Mein Kampf"; they don't have an overarching plan that they have been promulgating and thinking about for years. But the rhetoric they are using, the appeal, the emotions they are trying to incite in order to get their voters to the polls are precisely the kind of emotions and rhetoric that we heard then. That is a bad thing, because what scares me is that you can unleash emotions and behavior that you can't put back in a box. If people think it's fine to denigrate others, if people think it's ok to have a presidential candidate saying these are your enemies, all of them, and we define them by religion, which we have never done in this country, and anybody who is of that religion is suspect, you are going to see some bad things happen. Already you are going to see that. And that is something that really bothers me and that to my mind is totally contradictory to the history of the Republican Party.

The focus on Trump obscures that he is certainly no outlier among the large Republican presidential field. Other prominent candidates like Ted Cruz or Ben Carson and others have engaged in similar rhetoric, but perhaps haven't received as much media attention.

They haven't quite as much. But, yes, they are all getting on the bandwagon. They are saying this is effective, look at what he has done in the polls. I, as a candidate in these primaries, do not have to worry about the majority of the country. They don't vote in the Republican or Democratic primaries. It's only the Republicans and Democrats, and only a very small percentage of them. So what has been going on for a number of cycles is that the motto has been: "I get my base out better than you get your base out - I win."

And then, when it comes to the general election, it used to be that Republicans and Democrats would move to the center and compete for that vote. That was easier to do when you weren't so far out and extreme on the right or left. That is getting harder and harder. And what's happening is that you get a low voter turnout. With presidential elections we think we have done a great job when we get 54 percent of the people voting. Unfortunately, in a democracy that is the wrong response. Democracy doesn't ask much of us, but it does ask us to vote.

You have urged your fellow Republicans to defeat Donald Trump, whom you called the "scourge of our party." Do see any signs that this is happening?

Well, John Kasich is moving up in the polls in New Hampshire apparently. That's a hopeful sign as far as I am concerned. If he does do well there, it would earn him media and that could propel him to be more competitive in the other races. Then people could see that there are sensible alternatives to what we are getting everyday. And of course the press has its role. The Trumps and the Cruzes of the world make very quotable quotes. And they get published a lot. There are a lot of other issues that need to be discussed, but we are not getting those discussions because these fellows are out there just trying to mobilize their base.

If you looked at the Sarah Palin endorsement of Trump - and I didn't listen to the whole thing - some of what she said was just incomprehensible. But because she is who she is amongst the more extreme, more conservative members of the base, she is just what they want.

Christine Todd Whitman served as the first female governor of New Jersey from 1994 until 2001. She then led the US Environmental Protection Agency under George W. Bush from 2001 until her resignation in 2003 over demands by Vice President Dick Cheney to loosen air pollution rules. Whitman, a leading voice for a more centrist Republican Party, is the author of the 2005 book "It's My Party, Too: Taking Back the Republican Party And Bringing the Country Together Again."