U.S. Senator Elizabeth Warren (D-MA) shows company documents to Wells Fargo CEO John Stumpf during his testimony before a Senate Banking Committee hearing on the firm's sales practices on Capitol Hill in Washington, U.S., September 20, 2016. REUTERS/Gary Cameron

Sen. Elizabeth Warren became the first potential 2020 presidential candidate to raise the prospect of impeaching President Donald Trump. In a podcast interview on Wednesday with International Business Times reporter David Sirota, the Massachusetts Democrat also endorsed the idea of a single-payer Medicare-for-all health care system, and urged her party to promote that concept to voters across the country.

In the wide-ranging discussion, Warren explained why she chose not to endorse fellow progressive lawmaker Bernie Sanders in the 2016 Democratic presidential primary, as well as why she criticized her party for not delivering a more forceful economic message during the 2016 campaign.

Warren, who is up for reelection in 2018, has just released a new book called “This Fight Is Our Fight.”

What follows is a lightly edited transcript of the conversation that took place on May 17.

Sirota: "Why didn’t you run for president and do you have any regrets especially right now in the Trump era?"

Warren: "We can all look backwards now that Donald Trump is president and say, 'woulda, coulda, shoulda.' And, yeah, I wish Donald Trump were not President of the United States.

"But the question now has got to be what are we going to do going forward. It’s the threat that Donald Trump poses every single day—a threat that he keeps magnifying at every opportunity. So that’s where I am keeping 100 percent of my attention; I just don’t have anything leftover for looking backwards."

Sirota: "Why did you not endorse Bernie Sanders in the Democratic primary and have you gotten any flack for not doing that?"

Warren: "It was exactly what I said at the time. I thought the primary was good for the Democratic Party and good for America. I thought the primary gave us a chance to talk about a whole set of economic issues and social issues that otherwise would have been completely buried in the Republican 'clown show' that was going on.

"I thought that by having a sharply contested primary Democrats pushed issues to the fore that have changed our thinking. Issues around healthcare, the cost of college, even Glass-Steagall. Who knew that those would be the kinds of things that many people would become engaged in. I was proud—let me say it that way—during the primaries, I was proud to be a Democrat. I was proud that those were the issues we talked about and helped us decide which of the two candidates we’d end up with."

Sirota: "The polls in 2008 showed that Americans trusted Democrats far more on the economy than they do now. Eight years later, the Washington Post recently reported on data showing 'a shockingly large percentage of Obama/Trump voters say Democrats’ economic policies will favor the wealthy.' Why do you think that is? Why do you think Democrats are not more trusted on economic issues eight years after the Obama administration?"

Warren: "I think we haven’t gotten out there and fought for families the way we should. There’s a lot Democrats have done and I remind myself every single day that there are changes that Democrats would make in this economy if only we could get the Republicans to go along.

"My bill to cut the interest rate on student loans attracted every single Democrat but the Republicans filibustered it. My bill to expand Social Security got the sign-on from nearly every Democrat but the Republicans uniformly said no. So there are core differences between Democrats and Republicans and what we stand for every day are working people. But we sure didn’t get out there and make that argument to America’s families. And for that, I say 'shame on us.'"

U.S. Senator Elizabeth Warren (D-MA) puts her arm around U.S. Senator Bernie Sanders (I-VT) after introducing him at a Our Revolution rally in Boston, Massachusetts, U.S. March 31, 2017. REUTERS/Mary Schwalm

Sirota: "What is your view on how to view the people who voted for Trump?"

Warren: "There’s a lot of anger in this country and Donald Trump tapped into that anger. I see it as the anger is righteous anger. There are people who are angry because their kids cant get an education without getting crushed by student loan debt. People who are angry because they work hard all their lives and end up deeper and deeper and deeper in debt. People who are angry because they can’t look forward to a retirement with any dignity.

"There’s a lot of anger in this country and Donald Trump figured that out, he touched it like a raw nerve.

"He then told a story about how it was their fault and pushed off in the wrong direction. But at least he acknowledged the anger and I think that’s what Democrats have to do, as well. We have to admit there’s a lot that’s not working in this economy and then we have to tell our story about what we would do to make it better.

"For me, that’s what this is all about now. It’s the fundamental question, who does this government work for and Donald Trump said during the campaign, 'I’ll make it work for working people.' Then he got elected, and turned around and built a team of billionaires and bankers and handed the keys to the economy over to them. He signed off on one law after another to roll back protections so federal contractors could cheat employees out of their wages, so corporations that killed or maimed their employees could hide that, so that investment advisers could cheat retirees.

"And then the whole healthcare bill says it all. Donald Trump embraces a bill that knocks 24 million people off healthcare coverage, raises costs for middle-class families, raises costs for people over 50. And why? So that they can produce tax breaks for a handful of millionaires and billionaires.

"So Donald Trump made one set of promises and then turned in exactly the opposite direction. What progressives need to do now is to hold Donald Trump accountable for what he does, hold Republicans accountable for what they do and to make it clear we want to go in the other direction.

"We’re the people who want to see universal healthcare coverage, better outcomes at lower costs. We’re the people who want to reduce the cost of prescription drugs. We’re the people who want to see single-payer health insurance. We’re the people who want to reduce the cost of a college education and see more money got to K-12. We’re the people who want to rebuild America’s infrastructure and invest in medical research and scientific research. We’re the people who want to rebuild opportunity not just for some of our kids but for all of our kids. But nobody’s going to know that if we don’t get out there and fight for it."

Sirota: "Everybody says they're worried about foreign influence in American elections but both parties continue to take a pretty substantial amount of money from lobbyists, for instance, who represent foreign governments. Do you think if we are going to have a discussion about foreign influence on American politics do you think your part or both parties should be taking that kind of money? How worried are you about foreign influence in American politics?"

Warren: "Foreign influence, domestic influence, its money in politics that is choking off our government. So yes you are right to raise it in the context of Russia and other foreign actors, but let’s not kid ourselves. I have a whole chapter in my new book on the influence of money. And it's money contributions to politicians, but it is so much more.

"It’s about the armies of lobbyists that thunder through the halls of Congress. It is about the bought and paid for experts who show up to testify in front of Congress, who are on the nightly news and all being paid through shadowy money to help advance an industry point of view. It is about these so-called think tanks who are taking secret money. It’s even about the influence of giant corporations when they advertise and get different treatment in the press. It even affects the Supreme Court of the United States.

"I document all this through the chapter, and even there I'm barely scratching the surface. Money has perverted our economy, it means that Washington works for those at the top but less and less for anyone else."

Sirota: "What is the ideal American relationship with Vladimir Putin’s government?"

Warren: "Well, how about we start with the fact that Vladimir Putin’s government should not be interfering with elections in the United States, in Europe or anywhere else in the world. And the United States should make clear that when that happens we will do a full investigation and there will be consequences. We will have a response that will be painful to the Russians. That's where we need to start. This whole idea that right now our intelligence community has made clear, unambiguously, that the Russians interfered with the 2016 American election in order to influence the outcome. There's no ambiguity about this one. The evidence is clear on this. And yet, there has been no response from the United States government.

"The President of the United States continues to deny it, says there's nothing here to see, obviously, has tried to -- has fired people who have tried to investigate. And that has an impact not only on democracy here at home but on our relationship with Russia. So right now, for me, that's where we start. We do not let the Russians develop this additional weapon. That's what it is.

"Cyber attacks to interfere with an election are a weapon, a weapon that effectively undermine a country. We cannot let that happen and have no response at all. But that's where we are right now in the United States."

Sirota: "George Bush started a war based on false pretenses. President Obama did warrantless wiretapping and an extrajudicial assassination list. And Donald Trump has potentially, or allegedly, tried to stop an FBI investigation. When we talk about impeachment and law breaking when it comes to presidents, what is the threshold in your mind of something that becomes impeachable—a lawless action that becomes impeachable—in the context of those other actions?"

Warren: "I'm going to actually turn this a little bit and say, how about if we start with the part for which there is pretty much consensus, bipartisan consensus? And that is, that obstruction of justice is an impeachable offense. We established that during the Nixon years, that Nixon's cover-up, his effort to keep investigators from finding out what had happened during the Watergate scandal, was, in fact, an impeachable offense, and Democrats and Republicans agreed on that. That's the offense that if the facts that are alleged are proven, that's the offense in front of us right now. In fact, I should say from Donald Trump's own mouth, those are the facts that are in front of us right now.

"I think that is the question we answer. Impeachment is a legal standard, but it is also a political standard. There is a reason that this is not decided by the Supreme Court, this is not decided by, you know, some federal judge somewhere. It is decided by elected officials and is the ultimate check and balance in our divided government. And so, I'm going to just stick with the narrowest question, the one that is directly in front of us. And that is: does obstruction of justice rise to the level of impeachment? And the answer historically, bipartisanly, is yes."

Sirota: "Do you believe Donald Trump should be impeached?"

Warren: "Well, look at the evidence that's in front of us. Donald Trump has said that the reason, at least in part, that he fired Comey was because of Comey's investigation into the ties between Russia, the Trump administration and Donald Trump personally. And now with this latest revelation, which obviously we want to see the documents, we want to get Comey under oath, you want to make sure you've got all the facts in front of you. But the addition that Donald Trump asked Comey to halt his investigation of Flynn into the ties again, between Russia, the Trump administration and Trump himself, is obstruction of justice. If those facts are alleged, I mean we're right at the heart of it."

Sirota: "Should people be concerned that the criticism of Russia and the focus on Russia is escalating tensions with a nuclear-armed adversary?"

Warren: "I look at this in exactly the opposite direction. Vladimir Putin is an opportunistic thug who will take advantage of any opening he sees. The United States needs to get its act together. A president who blurts out top secret information, or who tried to thwart investigations into Russia's interference with our elections, is not helping us present a strong, united front to Russia. Instead, I think that we're opening the door for Putin to be even more aggressive.

"That's why we need to get this resolved. When I say 'this' I don't want to be ambiguous here. That's why we need to get a full investigation, get the facts in front of us, get all the documentation, get the witnesses in under oath, and resolve both what happened in the connection between Russia, the Trump campaign and Donald Trump, and what happened in terms of Donald Trump's efforts to interfere in the investigation. We need to get to the bottom of that, we need to do it quickly.

"This is one of those -- there's a reason not to let this thing drip, drip, drip. At least with Watergate, there was no overlay of national security. Now, there is. There is a strong overlay of national security. But I think that should urge us toward 'get it resolved,' get everybody back on the same place then, here in the United States, and have a coherent, disciplined approach to dealing with Russia going forward.

"And I'll add one part: and part of that approach has to be a developed response to cyber attacks, particularly attacks on our electoral system."