"It really is, I think, a warning sign for our democracy that we're seeing, perhaps, people whose political disagreements are now crossing the line into real-life violence," said Melinda Jackson, political science professor at San Jose State University.
And, lawmakers like State Senator Scott Wiener of San Francisco are facing ongoing threats.
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"It's not easy to be in elected office right now, whether you're in Congress, or the State Legislature, or city council, or school board. Elected officials are being targeted. I've definitely been targeted," said State Sen. Wiener, noting he's not surprised the Pelosi house is a target too.
"The right wing has been demonizing Nancy Pelosi in outrageous ways for many, many years, and it was just a matter of time, unfortunately, for someone to act on that," he added.
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The suspect David DePape told police of his plans to hold Speaker Pelosi hostage to "talk to her" and viewed her "as the "leader of the pack" of lies told by the Democratic Party, the eight-page complaint says.
"If she were to tell DePape the 'truth,' he would let her go and if she 'lied,' he was going to break "her kneecaps," the complaint alleges.
"By breaking Nancy's kneecaps, she would then have to be wheeled into Congress, which would show other members of Congress there were consequences to actions," it says.
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Jackson warns political polarization is taking a toll.
"To see the demonization of the side. You know, the other party members being portrayed as enemies and dehumanized, that's the kind of rhetoric that's really dangerous in terms of encouraging people to take violent action," she said.
Tara Campbell: "Are you taking any extra safety security precautions yourself?
State Sen. Scott Wiener: "I don't want to talk about my own security protocols, given that I've received thousands of death threats, including a bomb threat of my home, threats to shoot me -- I'm definitely careful."
The Associated Press contributed to this article.