I think you’re ultimately correct about the trend but that the underlying issue driving the uptick in political violence is being caused by other problematic societal trends. I don’t see the Democratic Party (official) endorsing gun violence, but I have seen a shift in the past decade or so when it comes to how much politics is the core of someone’s life. So it does make some sense to me that there would be an uptick in gun violence aimed at politicians as the same disturbed people who have been shooting at everyone else in America are suddenly consumed by politics.
Our lawmakers don’t live in a bubble outside of that reality, so I think it’s important for our leaders to do more to forcefully condemn violence and tone down the rhetoric. Part of that includes calling out those like Piker who are spewing the type of radical bullshit you bring up. But I think we also need to be careful when it comes to pretending that Nancy Pelosi calling for people to cause a scene is violent and incendiary rhetoric as the right-wing media is doing in the wake of these events.