Susan Sarandon hobbled into the restaurant in a cast boot and shiny Teamsters jacket emblazoned with the name “Sue.” But Senator Cory Booker’s first question for the actress was about a tattoo that runs down her back. (“It’s my kids’ initials — and my granddaughter’s,” she replied.)

When she returned the favor, challenging him to show his tattoos, Mr. Booker unbuttoned precisely one shirt button before admitting he didn’t have any. “I’m boring that way,” he said.

Ms. Sarandon, 69, had fractured her ankle while hiking in Colombia. But the injury scarcely slowed her down, as befits a busy actress and perhaps even more prolific activist. Her film career spans more than 45 years and includes “The Rocky Horror Picture Show,” “Bull Durham,” “Thelma & Louise” and “Dead Man Walking,” for which she won an Academy Award as best actress in 1996, her fifth nomination. Her latest film, “The Meddler,” will be released next month.

Ms. Sarandon has also spoken out on a wide range of social, environmental and political causes, including hunger and homelessness, H.I.V./AIDS, sex trafficking, the death penalty and mass incarceration. She has served as a Unicef Goodwill Ambassador since 1999.

Mr. Booker, 46, has also been a longtime activist for social justice. After Stanford University, where he played tight end on the football team, he was awarded a Rhodes Scholarship to Oxford University and earned a law degree from Yale in 1997. He moved to Newark, where he first worked as an advocate for low-income tenants.

The following year, Mr. Booker won a seat on the Newark City Council, and in 2006 he was elected to the first of two terms as mayor. In 2013 he won a special election to fill the seat of Frank R. Lautenberg, who died in office, making Mr. Booker the first African-American to represent New Jersey in the United States Senate. He went on to win the regular election the next year.

Famous for engaging his constituents and others on Twitter, Mr. Booker, a Democrat, has vowed to meet with all of his Republican colleagues in the Senate. His best-selling book, “United,” about finding common ground in a divided world, was published last month.

Over an early lunch at Il Cantinori in Manhattan, the pair traded notes about what brought them both to genealogy television shows, the forces that led them to activism (as well as acting and politics) and their thoughts about “political correctness” in this election year.

Philip Galanes: Let’s start with your creation myths. In high school, Cory sets up a whiteboard in his bedroom and writes his goals on it. That’s drive! Meanwhile, Susan gets her first film by accident, tagging along with her then-husband to his audition. True?

Susan Sarandon: That’s a legitimate explanation of how I got into the business. I wasn’t interested in acting. But it was the ’60s. I was a seeker. And what acting depends on is imagination, which creates empathy and also leads to activism.

PG: You weren’t being demure, like Lana Turner, getting discovered at the lunch counter?

SS: No. And it turned out that acting was a good approach to being in my life.

PG: Tell us about that whiteboard.

Cory Booker: That whiteboard isn’t my origin story. That’s like starting in the third act. My story starts with my dad, a black boy born to a single mother in a small town in North Carolina. It starts with my parents meeting in Washington, D.C., in the ’60s, at a time of incredible activism.

PG: Fair enough. But why the whiteboard?

CB: I wrote things down because I was a black kid from the first black family to live in an all-white town [Harrington Park, N.J.]. My parents had to fight to live there — literally, physical fights. And they were always pushing me to take advantage of my blessings.

SS: The whiteboard was his system. You were externalizing something that some people would have said in prayers.

PG: Tell us one thing you wrote.

CB: I wrote down the grades I wanted in every class. My parents were obsessed with my education. And I knew that sports would be my ticket to opportunity. Those were my two main goals in high school.

PG: Were your parents focused like that on you, Susan?

SS: My parents had no idea what parenting was. I’m the oldest of nine kids. My mother was raised in foster care in an orphanage. And my dad’s father died when he was young, and his mother was crazy. So these two met and, thanks to Catholic indoctrination on birth control, started having all these kids. Everyone did where I grew up. And I had to take care of them.

CB: My parents may have crisscrossed the race lines, but there was so much unfinished business. My father was not going to let me sit back and just consume my blessings. He wanted me to contribute, and to do that, you have to be mission oriented.

PG: Hence the whiteboard. Here’s a weird coincidence: You both appeared on TV genealogy shows, looking for a missing ancestor.

CB: My father and [maternal] grandfather both grew up not knowing who their fathers were. It left a stigma on them. I can still remember my grandfather’s anguish when he confessed it to me — and the word he used, “bastard.” It turned out that a white doctor had impregnated his mother when she was 14. That’s a common story in the twisted history of African-American families. Skip Gates [Henry Louis Gates Jr., the host of “Finding Your Roots” on PBS] explained to me that most African-Americans have some white blood in them. Same with white folks. There was lots of mixing in those family trees.

SS: And I had always been told that my grandmother, my mother’s mother, had been such a terrible parent that her kids were taken away from her and put into foster care. But it turned out that she was knocked up at 12 by my grandfather, who was in his 20s and lived next door. She pretended to be 15 so they could get married. Pretty amazing, right? Then she disappeared and got connected with the mafia. She went to the track in limousines, and jazz clubs, and dated Frank Sinatra. But not a kind thought was given to the fact that she was just a kid.

PG: It’s a big moment in our relationship with our parents, when we see how deeply affected they were by their parents.

CB: And it shows how connected we all are in ways we don’t understand.

PG: Which brings me to the big similarity between you: seeing others with compassion, whether they’re film characters, like prostitutes or death-row inmates, or citizens held down by generations of poverty.

SS: We’re all afraid of the same things. We all need the same things, too. I’m lucky to be in a business that’s almost forced compassion. I get to show you that you can identify with someone you never thought you’d be able to feel for. That’s what “Dead Man Walking” is about. We all make mistakes. But by connecting with the divine in each other, we can be redeemed.

CB: And as I get more decades under my belt, I see how small acts of decency ripple in ways we could never imagine. How could the civil rights marchers in Selma have predicted that by crossing the Edmund Pettus Bridge, they would trigger a bunch of lawyers in New Jersey to fight for fair housing for black families — one of them being mine? That connectivity inspires me every day. I take my job in the Senate very seriously. But there’s an old saying: Change doesn’t come from Washington, it comes to Washington.

PG: Have you always felt the need to speak up, no matter the cost?

SS: Even as a kid, I rotated my dolls’ dresses so every one got a chance to wear the good one. I think it’s innate. Or maybe it’s about being the oldest kid in the family, the caretaker? But I suffer more from having an opportunity to speak up, and letting it pass, than I ever have from losing a role or being threatened or having people say nasty stuff about me.

PG: Were you ever tempted to take a high-priced job in a big law firm?

CB: I reject the idea that the guy who comes out of Yale and goes to work in the projects in Newark is good, and the guy who goes to work for a white-shoe law firm is bad. We’re all mountain rangers. We all have peaks and valleys. I know a lot of people who work at nonprofits with men and women coming out of prison. But I also know lawyers at major law firms who help tremendously through pro bono work. Let’s not judge. Let’s draw inspiration from each other’s stories — successes and failures — and realize we’re all connected.

SS: I knew Sister Helen [Prejean] for about a year before Tim [Robbins] started working on “Dead Man Walking.” She didn’t come to the death penalty like Arnold Schwarzenegger in an action movie. She started by simply writing a letter to a man on death row. It was a small act of kindness, nothing heroic.

PG: That reminds me of the character in your new movie, “The Meddler”: a “smother mother” whose little acts of kindness change her life after her daughter tells her to back off.

SS: I have to admit, it’s completely self-serving. I do what I can to help, mostly by drawing attention to issues. But the people I see working in the grass roots, for years and years, they’re the people who give me hope, who show me the goodness in human beings.

PG: Let’s shift to an issue you’re both involved with: the mass incarceration of black men and boys. Cory wrote a moving chapter in his book about disproportionate arrests and sentencing, and the challenges of post-prison life. It’s a scary problem.

SS: What are you afraid of? You’re a privileged white guy. You’ll get off.

CB: That’s actually a good question. What are you afraid of?

PG: The scale of the problem: the number of inmates, the racial bias, the years in the making.

CB: But mass incarceration has only been a problem since 1980. Since then, our prison population has grown about 800 percent, 500 percent at the federal level. Before that, we expected our prison population to shrink. This problem is the result of policies we made in our lifetime.

PG: The harsh drug laws?

SS: Not to mention privatizing prisons that let companies and lobbyists make money by rounding up a population without a voice.

CB: I don’t want people to think, “It’s such a huge problem, what can I do about it?” We can’t allow our inability to do everything undermine our determination to do something.

SS: Well said.

CB: In California, they’ve gotten rid of “three strikes and you’re out” laws that were giving people life sentences for minor crimes. And it’s saved California taxpayers millions of dollars. We have states that have banned the death penalty. We can make big differences. We just can’t surrender to cynicism or feeling overwhelmed.

SS: It’s amazing that some of these guys, who made a mistake when they were 16, are getting out now. They’re telling their stories in documentaries and articles. Boys who learned to shave in prison. Because when you take a person and turn him into a concept, be it “the incarcerated” or “the refugee” or whatever, you’re denying his humanity. And that’s an act of violence. These are people, just like us.

PG: Can we take a stab at “political correctness,” a popular topic lately? The idea that people feel inhibited from saying what they think because it’s not socially acceptable. Is it better to have the ugly thing out in the open?

SS: Give me an example.

PG: When I was in school, I was almost relieved when someone called me a “fag.” I mean, I hated it, but I knew exactly where we stood.

SS: But that’s just normalizing hatred.

PG: But the hatred is already there. It’s not going away because they’re not saying it.

SS: Words are powerful. And whether we’re talking about kids in school or people running for president, slurs affect not only the person they’re aimed at, but also the person saying them and the people who hear them. When you had Trump being laughed at for making fun of people at rallies — and not being called on it for months — I blame our corporate media for a lot of that. It should have been talked about.

CB: There are always going to be people with hateful words in their mouths, and worse. Between 20 and 30 transgender Americans were killed last year for who they were. We had a church in South Carolina where someone walked in to kill black people specifically. But what concerns me more are all the good people who sit silent in the face of what’s going on. We all have a choice. We can do nothing and accept things as they are, or we can stand up and take responsibility for changing them.

SS: “Politically correct” is almost as good an expression as “right to life.” There’s nothing political about hatred, and there’s nothing correct about it, either. We need to have a dialogue about where the hatred comes from.

CB: To me, being silent in the face of injustice is the greatest threat we have.

PG: O.K., last question: As you may know, Susan is the co-founder of Spin, a Ping-Pong club in New York City and elsewhere.

CB: What?

SS: You have to come. It’s fun.

PG: But in a matchup with Cory, without a cast on your foot, would you beat him?

SS: Probably not.

CB: You sure?

SS: Maybe if we drank some tequila first.