Editor's Note: In this story, as originally broadcast, footage of the 2015 Freddie Gray street protests in Philadelphia was mistakenly used. It has been replaced with footage of the Freddie Gray protests in Baltimore.

On Thursday, we learned President Trump's former lawyer and fixer Michael Cohen, who is headed for prison, will testify in a televised hearing before the House Oversight and Reform Committee. It marked the beginning of season three of what's been called the "Donald Trump Reality Show" with a fresh plot, and new characters ushered in by voters in the midterm election who gave Democrats control of the House of Representatives. Among the recently empowered is Congressman Elijah Cummings, the new chairman of the House oversight committee. It has the constitutional authority to investigate anything it wants, creating serious problems for the Trump administration and making Cummings one of the most powerful people in Washington.

Elijah Cummings has been a familiar face on Capitol Hill for a long time, a respected 13-term Maryland congressman who has served on the oversight and reform committee under four different presidents. And he was handpicked by the Democratic leaders for this job.

Congressman Elijah Cummings

Rep. Elijah Cummings: We are in a fight for the soul of our democracy. And you've got to understand that. This is serious business.

You can dismiss the congressman's statement as partisan hyperbole, but part of the government is shuttered, four of President Trump's former associates are now convicted felons, ten of his original cabinet secretaries have left, four under a cloud of scandal. And there are 17 other investigations underway. Not counting the ones that are about to begin in the new Democratic House of Representatives empowered with the legal authority to compel testimony and demand documents.

Steve Kroft: So how are you gonna run this committee?

Rep. Elijah Cummings: What I'm gonna do is I'm gonna try to work with the Republicans as I have in the past. You know why? Because that's our job. And when it comes to subpoena, I know the power of a subpoena, having practiced laws. In order to do oversight, you gotta have documents. You gotta have emails. You gotta have information.

For the first two years of the Trump administration that kind of information was beyond the reach of house Democrats. The power of subpoena belonged exclusively to the Republican majority. As ranking Democrat on the House oversight committee, Cummings made 64 requests for subpoenas on things like White House security clearances, hurricane relief efforts in Puerto Rico, and the Justice Department's refusal to defend the Affordable Care Act. All of them were blocked by the Republican chairman.

Steve Kroft: You've asked the White House for a bunch of things. you've asked for documents connected to Jared Kushner's use of private emails. Child separation policy at the border. Have you ever gotten anything?

Rep. Elijah Cummings: Zero.

Steve Kroft: Nothing?

Rep. Elijah Cummings: Zero. --that's the point. Now, I-- I don't know if any president has ever done this. None. None that has ever said, "I'm not givin' you anything." For anything. Nothing.

Steve Kroft: But you're sitting here telling me you think somehow, miraculously, he's going to change.

Rep. Elijah Cummings: it's not about miraculous. It's about-- adherence to the Constitution. And the American people and the Congress is insisting that he allows us to do our job. Basically what the president has done and the Republicans have done, they've joined hands. And the Republicans have been basically not only blocking but become the defense counsel for the president. Okay. But no documents? I mean, come on.

Cummings with his wife, Maya Rockeymoore Cummings, and Speaker of the House Nancy Pelosi

Now as chairman of the oversight committee, Cummings no longer has to consult with the Republicans to issue subpoenas, initiate investigations or call hearings, and he has a much bigger budget and staff. So will Adam Schiff, chairman of the House intelligence committee, and Jerrold Nadler, chairman of the judiciary committee, but their inquiries will be limited to their specific jurisdictions. Cummings' committee has the authority to investigate anything inside or outside the federal government.

Rep. Elijah Cummings: We can look at anything.

Steve Kroft: You could--

Rep. Elijah Cummings: Anything.

Steve Kroft: --look at Interior, you could look at E.P.A.

Rep. Elijah Cummings: Anything. but the fact that we can look at anything is part of the problem. There's so much. No, I'm-- I'm serious. There's so much.

Steve Kroft: And you only have two years.

Rep. Elijah Cummings: Less than that. Actually, less than that. The Congress doesn't meet but so many days in a year. And all I'm saying is that we've gotta hit the ground, not running, but flying.

Some Democrats believe Cummings should go for the jugular and push for impeachment. He says it's premature, and he also wants to pursue other issues especially the high cost of prescription drugs. His staff has already sent out 51 letters to government officials, the White House, and the Trump Organization asking for documents related to investigations that the committee may launch. The issues range from the private use of government owned aircraft by cabinet members to the flow of foreign money into various Trump enterprises like his hotel in Washington.

Steve Kroft: You think he's making money off this job?

Rep. Elijah Cummings: Please.

Steve Kroft: A lotta money?

Rep. Elijah Cummings: A lotta money.

Steve Kroft: And-- and you say the Constitution and the laws say it's not okay?

Rep. Elijah Cummings: It's not okay. And, but this is the other piece. I still believe that people-- the average citizen, the guys on my block, they oughta know if the president is making a deal, whether he's making it-- making it in his self-interest or that of the country.

In response, the White House said: "these claims are completely baseless, but we cannot comment further about ongoing litigation."

Elijah Cummings has been in Congress for 23 years but he is not a creature of Washington. When he needs to be there he commutes from his Maryland district, an hour's drive to the north, where he represents 700,000 people and most of the city of Baltimore. He was born here 67 years ago to parents with fourth grade educations who'd been sharecroppers in South Carolina before moving north for a better life. His father worked in a chemical plant, his mother was a domestic. Both were pentecostal ministers.

Rep. Elijah Cummings: First it was religion, and then it was the education. My father, Steve, had a saying. He said-- he told us, "If you miss one day of school, that meant you died the night before." And he meant that. I did not miss one second of school between kindergarten and graduating from high school. Not one second.

He graduated Phi Beta Kappa from Howard University before earning a law degree at Maryland. He says he is one of the few congressmen who live in an inner-city, working-class neighborhood.

Correspondent Steve Kroft with Cummings at the congressman's home in Baltimore

Steve Kroft: How long have you lived here?

Rep. Elijah Cummings: 37 years.

He says he keeps a campaign poster in the front window so people will know where to find him.

Steve Kroft: So you like to be among your constituents?

Rep. Elijah Cummings: I like to be among my constituents. Let me tell you something man, if I don't do well in this block I'm in trouble. I mean, if you wanna take a poll, if I lost in this block I might as well go-- I might as well stay home.

When riots broke out in Baltimore three years ago after the death of a young black man, Freddie Gray, who was fatally injured in the back of a police van, Cummings gained national attention walking the troubled neighborhoods trying to keep the peace. He is part of the city's fabric.

But now he has stepped onto a much larger stage, under the bright lights of the oversight committee.

Rep. Elijah Cummings: Well, I sit here. And the Democrats'll be all over here. And the Republicans will be over there. Our hearings can go anywhere from an hour and a half to 11 or 12 hours.

Steve Kroft: So you got a good, comfortable chair.

Rep. Elijah Cummings: Got a good, comfortable chair. And I gotta tell you, Steve-- standing here, it just-- it sorta gives me chills in a way because I think about my journey to this chair.

After years as the committee's ranking minority member, he is ready to wield the gavel and the subpoena.

Steve Kroft: You've got a lotta power. But you don't have unlimited power. I mean--

Rep. Elijah Cummings: No.

Steve Kroft: --and the Republicans are going to put a lot of obstacles in your way.

Rep. Elijah Cummings: Sure. I expect that. Now, there's one big elephant that's sittin' around here that we don't know-- what it's gonna yield. And that is Mueller's report. I don't know what that report is gonna have in it. One thing I do know, though, is whatever it is, even if it-- if it exonerates the president, fine. But this I do know: I want whatever it is, for the Congress to have it, and I want the public to have it, so that everybody can make a judgment.

Steve Kroft: Do you think it's possible the Republicans will try and suppress the report?

Rep. Elijah Cummings: I hope not. But that's a possibility. But I hope not. I hope they don't.

Cummings' Republican foil on the committee is Ohio's Jim Jordan, one of the president's most loyal and enthusiastic supporters.

Steve Kroft: You've known Elijah Cummings for a while. How would you describe your relationship?

Rep. Jim Jordan: Well, look, there's-- there's not much of anything that-- that Mr. Cummings and I agree on, policy-wise. But-- I certainly respect his toughness-- his tenacity. You know, he's demonstrated that he's-- he's a fighter and I kinda-- my background is such that I kind of appreciate that.

A founding member of the Freedom Caucus, Congressman Jordan is a one-time college wrestler and coach, still known for his scrappiness. He's seldom seen wearing a jacket, and always ready to go to the mat.

Congressman Jim Jordan

Rep. Jim Jordan: Taxes have been cut, regulations reduced, the economy growing at an unbelievable rate, lowest unemployment in 50 years. 312,000 jobs added last month alone. Gorsuch and Kavanaugh on the courts. We're out of the Iran deal. The embassy's in Jerusalem. Hostages are home from North Korea.

And oh, by the way, there's a new N.A.F.T.A. agreement. So it's an amazing record and that's what I know about the two years that we've had Donald Trump as President of the United States.

Steve Kroft: After the midterms, you wrote a letter to the Republicans saying, "You must valiantly defend the president." Is that your job?

Rep. Jim Jordan: My job is getting to the truth. If the president is getting a raw deal I'm going to defend him.

Steve Kroft: I feel like I would be remiss in this if I didn't point out that truthfulness has not exactly been President Trump's strongest asset.

Rep. Jim Jordan: Well, I mean, Steve, look, this-- this president's probably been attacked more than any president that-- in my lifetime. And here's what I know. Over the last two years, in spite of the unprecedented attacks that have come against President Trump, the last two years have been amazing.

Chairman Cummings wouldn't disagree that the past two years have been amazing, but in a much different way.

Rep. Elijah Cummings: I don't think the other presidents-- called a lie the truth and the truth a lie. I-- I'm gonna tell you, that's what makes the relationship so difficult. It's hard to trust. You-- you wanna believe that if you make an agreement with someone, and I believed that with the other presidents it was this way, their word was their bond. I don't know how to compare. I-- I-- I don't. And I'm not tryin' to be smart.

Steve Kroft: We're in new territory here.

Rep. Elijah Cummings: Yes, it's new territory.

The new territory now includes a beefed-up White House counsel's office. It has added more than a dozen new lawyers to fight what it anticipates will be a barrage of requests and subpoenas from congress.

Steve Kroft: What happens if you issue a bunch of subpoenas and the administration doesn't respond? Or invokes executive privilege.

Rep. Elijah Cummings: We probably will end up in the courts. And one of the interesting things about the courts is that our president has been making sure that some of the most conservative judges are being p-- appointed-- to the federal bench. And I think he relies on that, and I think that he assumes that the courts will-- will possibly be, it all depends-- be helpful to him.

It promises to be a demanding time for a man who spent nearly six months in the hospital over the last year and a half for heart and knee surgery. As he showed us the victory prayer chapel, a church founded by his mother, Congressman Cummings relied on a cane and a walker. He says his chairmanship will be a physical burden on him, but his strong faith and awareness of his mortality will see him through.

Steve Kroft: Do you feel like you have the strength--

Rep. Elijah Cummings: Oh yeah, man--

Steve Kroft: --and the stamina to do this?

Rep. Elijah Cummings: Oh, I'm good. I'm good. Like I tell my-- my constituents, "Don't get it twisted. You know, I may-- my knee may be hurtin' a little bit, but my mind is clear. My mission is clear." And I am prepared and able to do what I have to do. And I will do it to the very best of my ability, so help me God.

This story was produced by Maria Gavrilovic. Associate producer, Alex Ortiz.