Mayor Pete Buttigieg, one of the two-dozen Democrats running for president, believes hesitation by some white Americans to speak frankly and openly about race and socioeconomic privilege is a major roadblock in elusive efforts to enact comprehensive criminal justice reform and address racial disparities in the U.S.

"I think the challenge for white America is to realize that we can't be defensive about this," the mayor of South Bend, Indiana, told CBS News in an interview Sunday.

"When somebody is saying that we are benefitting from living in a system that creates privileges associated with systemic racism, we can't kind of retreat into this idea that, 'We're being personally attacked, so we're not going to want to talk about that.' Or that, 'Hey these were distant historic problems, we can't be held accountable for dealing with that,'" he said. "No."

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Buttigieg said he's concerned about the long-term effects of inaction when it comes to racial inequality in America.

"I am worried that in different ways we may not be able to imagine, in the 21st century, if these inequalities keep getting worse, then that could once again threaten to unravel the American project," he said.

The millennial mayor and veteran of the war in Afghanistan also weighed in on President Trump's widely condemned racist tweets about four progressive congresswomen of color. "It's racist and it fundamentally misunderstands America," he said.

Despite impressive fundraising numbers, the openly gay Midwestern mayor has struggled to make significant inroads among communities of color — a key constituency in Democratic primaries. In an effort to appeal to those communities, he recently released "The Douglass Plan," an ambitious proposal named for the famous 19th century abolitionist to invest in communities of color and try to dismantle systemic racism.

Back home in South Bend, several events have strained Buttigieg's relationship with the city's African American community. He still faces tough questions for firing the city's African American police chief in 2012, and last month he was strongly criticized by some of South Bend's minority residents for his handling of an incident in which a city police officer killed an African American man. That officer, Sgt. Ryan O'Neill, resigned on Monday.

During the first Democratic debate, Buttigieg conceded he has not done enough to diversify the city's police force.

The following transcript of the discussion between Buttigieg and CBS News political correspondent O'Keefe on race and criminal justice has been lightly edited for length and clarity.

ED O'KEEFE: Thank you Mr. Mayor for doing this. Let's talk about some stuff that's going on today or that's in the news right now. I imagine you've seen what the president tweeted earlier today some of your Democratic colleagues in Congress today saying essentially they should go home to where they came from. Obvious outrage from a lot of Democrats about that but curious your reaction to his decision to once again interject in party politics and to say what he said.

BUTTIGIEG: Well, it's wrong, it's racist and it fundamentally misunderstands America. One of the reasons we set up this country, one of the things we celebrate in freedom and democracy of the United States is you can criticize your president. You can criticize the ways in which the country falls short of its values.

And that makes you more, not less, loyal to this country whether we're talking about naturalized citizens or many of the people he was talking about who were born right here in the U.S. When you become a citizen, you are an American and questioning somebody's Americanness because they disagree with you — is about one of the most un-American things I can think of.

ED O'KEEFE: In the plan you released last week — the Frederick Douglass Plan — you had alluded to that white Americans especially have to talk about systemic racism.

BUTTIGIEG: That's right.

ED O'KEEFE: President may have just presented you a great opportunity to do so, but why is that conversation perhaps more important for white people to have?

BUTTIGIEG: Well, for too long this has been talked about as a kind of specialty issue, something that people of color talk about and something that white politicians talk about with people of color and not the rest of the time. Systemic racism is something that diminishes all of us.

Of course its worst effects are for its victims, but our entire country is held back through the inequality and the mistrust that it creates. The mistrust of institutions. The mistrust of a country that has not served everyone equally, and I am not just talking about far off historic harms like slavery. I'm talking about housing, unemployment and criminal justice discrimination that is taking place in our lifetimes, in living memory.

And I think the challenge for white America is to realize that we can't be defensive about this. When somebody is saying that we are benefitting from living in a system that creates privileges associated with systemic racism, we can't kind of retreat into this idea that, "We're being personally attacked, so we're not going to want to talk about that." Or that, "Hey these were distant historic problems, we can't be held accountable for dealing with that." No.

The force that has come closest across American history to actually ending America was white supremacy. That was the Civil War. And I am worried that in different ways we may not be able to imagine, in the 21st century, if these inequalities keep getting worse, then that could once again threaten to unravel the American project. The levels of inequality we're seeing — much of it driven by racial inequality — are something that very few countries can survive intact.

And if we don't all come together to deal with this — not as an issue for some, but as an issue for us all — then I worry that the entire American project will be weighed down.

ED O'KEEFE: You say that this is a conversation that white people need to have and not be defensive about it. That's going to be music to the ears of black, Latino, Asian people in this country who, as you said, you know, obviously want to hear about this and believe it to be true.

It's going to be a tougher sell though among white Americans who think things are fine. Or, why are they talking about this again? Or the gentleman that you had an interchange with a few weeks ago who suggested that if black people just stop committing crimes, there won't be a problem. I mean, that's what you're up against if you try and have this conversation.

BUTTIGIEG: But we've got to have this conversation because time's running out. The reality is we can't separate the chaos of our politics, the division, the wrongfulness coming from the White House but also through our communities from all the pernicious effects of systemic racism. As long as this is two different countries for people of different races, which, if you look at the statistics on things from life expectancy to income to experiences, even for the exact same offense with the criminal justice system, it really is like two countries.

As long as that happens, then we don't have the strength of being one country. And if you want to know whether this impacts you, white or not, think about the fact that foreign adversaries are now using racial inequality and division as a national security weakness, pitting Americans against each other over this and treating it as a wedge that can weaken America. And they're right, this is a deep weakness in an otherwise strong, and robust American system. It's why we got to deal with it in our lifetime.

And what we've learned the hard way is just taking a racist law and replacing it with a neutral one is not enough to bring about equality. These things don't wash themselves out of the system without intentional action. They actually get worse. For the same reasons that a dollar saved because of interest grows over time, so does a dollar stolen. And many of these wrongs that started a long time ago are only going to get worse with time if we don't make the investments in home ownership, in education, in health equality, in a better criminal justice reform system, in helping with entrepreneurship to create more jobs, and by the way, if black entrepreneurs are thriving, they're creating more jobs for people of color and more jobs for all of us.

[...]

ED O'KEEFE: You released this Douglass Plan. And you know that a lot of the chatter has been, "Well, interesting guy, raised a lot of money, doing well in the polling, but struggling to win over black and brown voters."

So you release this plan, and then what? What happens next? How do you build up that support?

BUTTIGIEG: Well, first of all I've got a responsibility to communicate about that plan. I believe it is the most comprehensive plan put forward in this campaign on how to make sure we lift up the conditions and opportunities for black Americans. But it's still my job to go out and share that idea.

There's a broader issue though, which is that I still need to work to get known in a lot of communities. And that's certainly true when you're new on the scene and you are not yourself from a community of color. It's certainly true in reaching out to black and brown voters who often want to know what you're made of in a way that takes time to explain. But I'm committed to doing that work, that's why we're reaching out to various groups, both in terms of big public appearances. And when the cameras are off, having smaller conversations with activists, with pastors, with residents.

Making sure that in the same way that it worked at home. For me to put in the quantity time that got the kind of support I needed to get reelected with help from the black community in South Bend. That that will serve me well winning the nomination too.

[...]

ED O'KEEFE: One of the aspects of your Douglass Plan, I meant to ask about. You're essentially, correct me if I'm wrong, pushing to reduce incarceration rates by 50 percent.

BUTTIGIEG: That's right.

ED O'KEEFE: There are some studies that have looked into what you are proposing, others have suggested this as well, that means you'd either have to release violent offenders or you're somehow tabulating state and local incarcerations which wouldn't be under federal control. So how do you get to 50 percent?

BUTTIGIEG: So I believe that federal leadership can reduce those incarcerated at the state level and local level pretrial as well as what's happening federally. And we've got to do all of the above in order to meet this goal. The bottom line is, research tells us that we can and should have lower incarceration and that that will not be associated with an increase in crime. After all, if incarceration made everyone safe, we'd be the safest country in the world because we're pretty much the most incarcerated.

But it does mean that we work with states and localities, by the way, many of which are trying to do this, but don't have the resources. And again, we see this in my area of the Midwest, where you have highly successful, very promising programs for alternatives to incarceration. Drug diversion programs, for example. But there are long waitlists and backlogs because they don't have the resources to do it. The Federal Government should be helping because there's also a return to investment in making sure people are not incarcerated and when they leave, reintegrated successfully. We have learned that it is simply false that a tax cut for the wealthy will pay for itself. But it is absolutely true that having fewer people incarcerated pays for itself in the long run.