An article in the paper ("A Reverb Epidemic" by Thi Nguyen) caught my attention, considering "radical polarization." Politics jumps out first, with people seemingly having extreme (and possibly outrageous) positions from both left and right; however, all kinds of topics are subject to extreme positions: religion, diet, sports. The "social media bubble" is one possibility, but the author has a broader perspective. Nguyen defines "epistemic bubbles" as "what happens when insiders aren't exposed to people from the opposite side," such as the exclusive focus on a one-sided social media feed. An "echo chamber leads its members to distrust everybody on the outside of that chamber," and refers to a 2008 book "The Echo Chamber" on right-wing media: "Rush Limbaugh and the Fox News team systematically manipulated whom their followers trusted. Limbaugh presented the world as a simple binary--as a struggle only between good and evil. ... Anybody on the outside was malicious and untrustworthy." "In an epistemic bubble, outside voices aren't heard. In an echo chamber, outside voices are discredited." Nguyen believes the major problem is echo chambers rather than epistemic bubbles, because members are exposed to the other side, but don't believe them (on climate change "scientific institutions and mainstream media have been corrupted by malicious forces"). "Echo chamber members have been prepared to face contrary evidence. Their echo-chambered worldview has been arranged to dismiss that evidence at its source. ... An echo chamber member distrusts the standard sources. Their trust has been redirected and concentrated inside the echo chamber."
As a moderate, I've faced (and occasionally) argued with people with different perspectives (politics and global warming especially). It doesn't seem to matter that I'm a moderate; in their minds I'm either a right-wing fascist or left-wing commie.