Democratic consultant Brent Blackaby's relationship with his conservative uncle had survived the controversies of the George W. Bush administration and weathered chain emails from his relative positing that President Barack Obama is a Kenyan-born Muslim.

What it couldn't take was Donald Trump.

Soon after the Republican presidential nominee suggested last week what "Second Amendment people" could do to stop Hillary Clinton, Blackaby severed Facebook ties with his Trump backing-uncle, and in the process got into a nasty name-calling spat that consumed parents, siblings, cousins and anyone else following along in his 2,300-friend social network.

"Seriously, what kind of crack are you smoking?" he wrote after his uncle in Scottsdale, Arizona, surfaced conspiracy theories about a secret Democratic plan to form a "one world government," part of a three-day social-media firestorm (excerpts of the exchange below) that drew in parents, siblings, cousins, and anyone else with an opinion.

This was the awkward Thanksgiving dinner conversation about politics everyone is warned to avoid, only this time it played out in the far-from-private forum of Facebook. Blackaby's family spat wasn't the first either. Not by a longshot.

The Silicon Valley behemoth says more than 100 million Americans this year have generated four billion posts, likes, comments and shares about the presidential campaign and in the process prompted all manner of hand wringing and division among users more accustomed to glorious ignorance about their friends' political opinions.

Facebook says it doesn't have data about how many people have been unfriended, hidden or just plain muted because of their postings about the election. But the anecdotal evidence is clear: People are growing more uncomfortable with so much online sharing about politics this cycle, and many are looking for an off ramp by winnowing down their feeds.