They like to say that the statistics show that the majority of political violence comes from the right, but I've yet to see any of them give a list of examples. They may name one or two random acts, but nothing that compares to what the left is constantly doing.
Some possible explanations:
1. I suspect the left is undercounted in crime statistics. We've all seen them firebomb stuff, but they probably do it in areas where they're less likely to get prosecuted for it.
2. The violence supposedly coming from the right is astroturfed by people like the SPLC. Then of course, you have the FBI entrapment in the Whitmer "kidnapping conspiracy", and I doubt that's the only time they've tried something like that.
3. While the left is guilty of certain violent acts, they're also kind of inept at it. They're much better at social engineering, such as trying to influence opinion (e.g. pretending to be a disillusioned right-winger), or intimidating without outright violence.