WASHINGTON – President Donald Trump has called Democrats "evil," described the media as "the enemy of the people," dismissed opponents as having a "low IQ" and encouraged supporters to chant "lock her up" at the sound of Hillary Clinton's name.

But as authorities intercepted suspicious packages mailed to his rivals for a second day Thursday, the White House sought to dial down the rhetoric while simultaneously blaming the media for the nation's charged political atmosphere.

After years of intentionally poking his Twitter fingers at what remains of civil discourse in Washington – a tactic Trump himself admits is intended to get a rise out of Democrats – experts who study political language say the bomb-like devices delivered to prominent Democrats and media figures were probably inevitable.

"It doesn’t have to trigger everybody, but you can't predict who it will make violent," said Jennifer Mercieca, a historian of American political rhetoric and an associate professor at Texas A&M University. "If you have a pervasive culture of weaponized communication, statistically, someone will be violent."

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Over the course of a single week this month, Trump took to Twitter to describe a former porn star who accused him of an affair as "horseface," labeled Democrats the "party of crime" at a rally in Montana, called a Democratic candidate in Texas a "flake" and gleefully employed the word "mob" to describe his political opponents.

Trump's words changed markedly this week after authorities intercepted packages mailed to former President Barack Obama, Clinton, former Vice President Joe Biden, Democratic Rep. Debbie Wasserman Schultz of Florida , Democratic Rep. Maxine Waters of California, the New York offices of CNN (which was addressed to former CIA director John Brennan) and others who have been on the receiving end of the president's barbs.

At a rally in Wisconsin on Wednesday, Trump refrained from calling the media "fake" – a line that always prompts supporters to turn around and jeer at the press – or blasting Democrats with this his trademark nicknames. The president even spoke in a more somber tone, the kind of voice he is more likely to use at the White House.

"Do you see how nice I'm behaving tonight?" Trump told supporters in Mosinee. "This is like – have you ever seen this? We're all behaving very well."

More:Trump tones down attacks, calls for civility after devices mailed to Democrats

The restrained approach continued Thursday, as the president spoke at the Department of Health and Human Services to announce a new initiative to lower drug prices. Though he briefly tweaked his predecessor, noting "Obama didn’t come here" after the 2010 Affordable Care Act was signed into law, he mostly remained on script.

"For decades other countries have rigged the systems so that American patients are charged much more and in some cases much, much more for the exactly same drugs," Trump said. "It's wrong. It's unfair."

The White House, meanwhile, pushed back on a chorus of criticism from Democrats and academics suggesting Trump's rhetoric created a charged political atmosphere where violence is possible. White House Press Secretary Sarah Sanders rejected the idea that the president was complicit in stirring up animosity directed at Democrats.

"The president is certainly not responsible for sending suspicious packages to someone, no more than Bernie Sanders was responsible for a supporter of his shooting up a Republican baseball field practice last year," Sanders said, referring to a shooting in Virginia that left House Majority Whip Steve Scalise, R-La., critically injured.

Sanders has a point, experts said: There is no way to directly tie the packages to Trump's rhetoric. It's impossible to trace any attempt of violence to a single speech. But, they said, it's also not realistic to pretend the environment Trump creates with his anti-politically correct language hasn't had an impact.

Bryan Gervais, a political scientist at the University of Texas at San Antonio, said that "like-minded" incivility generally does not inspire anger or violence. In other words, those rooting for Trump are "in on the joke" and view the statements as a way to put political opponents on defense. The people most likely to get angry are the targets of his barbs.

"Political incivility doesn't do that much to induce emotional reactions like anger – it’s usually the opposite," Gervais said.

But there's a huge caveat, he said: "It really depends on the individual."

Democrats continued to focus on Trump's previous harsh comments, questioning the sincerity of the president's sudden call for comity. Senate Democratic leader Chuck Schumer and House Democratic leader Nancy Pelosi, both of whom have been the targets of Trump's barbs for years, said "the president has condoned physical violence and divided Americans with his words and his actions."

Former CIA director John Brennan, who has sparred publicly with Trump and who was an intended target for one of the packages, said Trump needs to "stop blaming others."

"Look in the mirror," Brennan wrote on Twitter. "Your inflammatory rhetoric, insults, lies, & encouragement of physical violence are disgraceful."

Those who have studied Trump's language closely predicted the president's sharp elbows would return soon, particularly as the country heads toward a pivotal midterm election next month that will decide control of Congress.

Paul Achter, associate professor of rhetoric at the University of Richmond, accused the White House of using a "cop out" argument to absolve Trump from any responsibility.

"Of course you can’t directly trace this back to Trump, but symbolic violence is a thing," Achter said. "Words create a context for violence where violence becomes more likely."