JOHN YANG: Studies show that over the past decade, there's been a steady increase in threats against public officials and in political violence like yesterday's assassination attempt.

Ali Rogin takes a closer look at how we got to this point.

ALI ROGIN: Those instances of political violence also include attacks on local politicians, members of Congress and their spouses and political disagreements that turned deadly.

Cynthia Miller-Idriss is the director of research at American University's Polarization and Extremism Research Innovation Lab.

Cynthia, thank you so much for being here.

This was a shocking event in a horrible tragedy for many Americans the first time that they've witnessed the attempted assassination of somebody who served as president.

But of course, there have been many other acts of political violence in recent memory, including the attack on Nancy Pelosi's husband, Paul, in 2022.

There was the congressional baseball practice shooting that injured Congressman Steve Scalise and 2017 plus many other attacks against local officials.

Why are we experiencing this uptick in political violence?

CYNTHIA MILLER-IDRISS, Director, Polarization and Extremism Research Innovation Lab: Well, first, I have to say it should be condemned.

Of course, we have to condemn the attack on former President Trump.

You know, one of my earliest political memories was the assassination attempt on President Reagan.

I think we are back in an era in which political assassinations are becoming a tactic again of in which people seek a solution to what they think are their political problems.

And that's part of the rising violence that we're seeing across the board politically, and also part of the rhetoric that has been increasing on polarized lines that positions us versus them and existential terms, so that the other starts to seem like a threat that has to be eradicated.

So it's a problem at the elite level, and it's a problem among ordinary conversations as well.

ALI ROGIN: And you mentioned the rhetoric, members of both parties have been coming out saying that both sides need to tone this down.

How much of that is at issue here?

CYNTHIA MILLER-IDRISS: The issue of political rhetoric that's divisive and even violent among elites is a huge problem.

And it has been a huge problem for many years on both sides.

However, I'm actually just as concerned about what I'm hearing from people I know and love even seeing on social media, things like you reap what you sow in response to this event.

That's just as problematic.

You have a lone actor who is not only motivated by elites who mess up, but also by ordinary citizens who give up and who lean into the idea that violence is a solution to any kind of political ideas or problems.

ALI ROGIN: One of NewsHour polls found earlier this year that one in five respondents believe Americans may have to resort to violence to get their own country back on track.

That seems like a high number.

What's your take?

CYNTHIA MILLER-IDRISS: It seems high, but it's accurate.

I mean, that's exactly the kind of data that we've been seeing.

We're seeing increasing support for political violence and also increasing willingness to engage in it among ordinary Americans.

And that's what I mean about everybody seeing this as a moment of reckoning for themselves and their own behavior, not just to wag fingers at the elites, and politicians who are behaving badly.

But to think about what you do across the dining room table, what you're doing in your classrooms, what you're doing with your colleagues and your neighbors.

Because anytime you're justifying that kind of violence, you never know who's going to overhear that, or how that contributes to the overall climate in which violence is seen as a solution.

ALI ROGIN: And to that end, do you think that everybody has a role here in lowering the overall temperature that's got us to this very tense point?

CYNTHIA MILLER-IDRISS: Absolutely.

I think everyone has not just a role, but an obligation to lower the temperature to see our basic humanity to see that no one deserves to be shot, no matter how much you disagree with what they say politically.

And to also take steps to kind of curb things like misinformation, stop retweeting it, I mean to be critical consumers, and good citizens about what you share.

I think that's one of the big takeaways here is that people have a role to play and an obligation to do it.

ALI ROGIN: And in terms of response to this, this particular event, what are you concerned about happening in terms of people perpetrating potential violent responses?

CYNTHIA MILLER-IDRISS: Another thing that ordinary people can do is to be a little bit vigilant in the coming weeks and months, because unfortunately, an event like this does create the risk that you have both kind of militant groups who see now that they may have to step up, they think and protect this candidate, as we've seen in the past, and you also see the risk of reprisal attacks.

And so, this is a real moment for people to pay attention to be vigilant, if you hear someone you know, saying something, tone it down, you know, try to correct their statements and their behaviors and steer them away from the idea that violence is a solution to anything.

ALI ROGIN: Cynthia Miller-Idriss, Director of Research at American University's Polarization and Extremism Research Innovation Lab.

Thank you so much for being here.

CYNTHIA MILLER-IDRISS: Thanks for having me.