MICHEL MARTIN, HOST:
As we heard, Cesar Sayoc allegedly sent pipe bombs to individuals and a news organization, CNN, that President Trump frequently criticized. Last night, though, the president bristled at suggestions that his rhetoric is to blame for what he called the sinister actions of one individual. But we wondered if it's fair to ask if his tone has created a climate conducive to violence, like the mail bombs or the carnage at a synagogue today. I talked about this with Professor Kathleen Hall Jamieson, an expert on political discourse at the University of Pennsylvania's Annenberg School of Communication. We talked about the complaint of critics that President Trump has normalized a, quote-unquote, "othering of people" - attacks on political opponents as enemies.
KATHLEEN HALL JAMIESON: The president of the United States has a unique capacity to determine what are accepted political norms of discourse. And, to the extent that he expands those outside the normal boundaries, he says to everyone else, those expanded boundaries are now boundaries in which you cannot only speak but speak in public and not be afraid of sanction. And for that, we have to hold Donald Trump accountable.
MARTIN: I mentioned to you that we've been traveling around the state this week, meeting with all kinds of people. I spoke with a group of Trump supporters. We're going to hear from them later this weekend. They profess not to have heard any of the president's attacks on individuals, the media. I - you know, I was asking them about the tone that the president sets, but they professed not to have heard any of this.
JAMIESON: We all live, to some extent, within our own like-minded communities. And when we live inside our own media bubble, we're far more likely to see the world through the filter that it offers. So, to the extent that the president is saying things that have been normalized inside that constituency, they're not going to remember it specifically. It's going to be a background assumption.
MARTIN: There have been many divisive moments in American history, many violent moments - I mean assassinations, politically motivated bombings - the civil war, for that matter. How do you contextualize this era as a person who's studied communication throughout our history?
JAMIESON: The difference between then and now is that now exists an environment in which these horrific acts - that is, bombs were sent to people - yielded two and a half or so days of people asking whether or not these were fake or not, whether or not Donald Trump was or was not to blame for them. What it suggests is we've lost our capacity to be horrified by this sort of action. We've lost our ability to say, whether they were Democrats or Republicans, we disapprove of this action profoundly. And we're going to ask, is the climate that is conducive to it something that we are in any way contributing to?
For example, when someone is driving around with the van with pictures that suggest dismemberment - the pictures that show people in the crosshairs of a gun - that that was normalized enough in a community that that person thought it was acceptable to drive around with that van and then attend a rally and park that van - go to a rally where some of those sentiments within the audience were expressed on T-shirts.
How have we managed to normalize that so much that, in this moment, we couldn't come together and say, whoever did this, this is highly problematic. We disapprove of it, and we are going to look at the broader culture and ask how we minimize the likelihood that it will ever happen again.
MARTIN: That is Kathleen Hall Jamieson, professor of communication at the University of Pennsylvania's Annenberg School for Communication. Her latest book is "Cyberwar: How Russian Hackers And Trolls Helped Elect A President - What We Don't, Can't And Do Know."
Professor Jamieson, thank you so much for talking with us once again.
JAMIESON: It's good to be with you. Transcript provided by NPR, Copyright NPR.