Let's re-frame this discussion then.
People see the George Floyd video, and that sparks protests about police killing black Americans. Those protests then devolve into riots in some major US cities.
Key Point: Those riots and protests weren't just because of George Floyd, although his death likely elevated the issue. They were about the 'systemic killing of black people by police.' Which is a lie. Period. The Washington Post created a database to try and prove the theory... and they came up empty, along with other journalistic/academic outlets. That reality didn't dissuade prominent media personalities, our current VP, and others from creating bail funds for those doing the rioting, and going along with that lie... because it made them powerful.
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Fast forward 6-8 months.
Some people see that their state voting laws are being changed without their legislature's consent due to legal action by the Democratic party/and or action from Democratic state officials, and that bothers them. Election night rolls around, and more people see "massive dumps of mail-in votes" that happened throughout the night, and several uncorroborated accounts of "fraud" being perpetuated. When coupled with that previous discontent, they believe the election is likely stolen. (Then) President Trump seizes on that narrative... because that gives him political power.
Tying it together: Both the cases rely on factual things that happened to base their alternate realities. George Floyd did die at the hands of a cop. States did have their voting laws changed to boost mail-in voting. Attached to those truths are an entire web of lies that create the full conspiracies, and thus build the emotional fever required to sustain a movement. Cults work in very similar ways, actually. You could even say the same thing about QAnon... with the factual basis being Jeffrey Epstein.
Moving on though, both sides took those false ideas and engaged in violence to support them. For BLM it was rioting and looting. For the right it was Jan 6th.
We can debate over which was "bigger" or which made the larger "impact," but fundamentally they are the exact same thing. Political violence committed because of a conspiracy. A lie.
Trump didn't invent the fraud conspiracy, he simply weaponized it for his gain. Just as Kamala Harris and other Democrats didn't invent the lies that BLM used. They simply weaponized it for their gain.
Both sides in a deeper way understand this, which is why the debate naturally comes down to which side is more morally righteous. Ex. "You seriously can't compare racial oppression to a crazy stolen election theory." Which is an attempt to add slavery/Jim Crow/racism to their side of the seesaw in a clever slight of hand... by calling you a racist.