You’re presenting the data for whether it’s okay to be happy about a political figure’s death, not whether it’s okay to cause one. There’s a section about this you should read starting with “YouGov's polling doesn't suggest that young people or liberals are more pro-violence in general”, and in particular the stark divide about self-defense. None of this is great, but it’s hardly surprising that a minority of younger people are more supportive of violence than people who have more life experience and fully-developed frontal cortexes.
But as for "causing" violence, they also asked whether "political violence is ever justified", and the difference between left vs. right there was even more — 25% vs 3%.
Given the right's overall reaction to things like January 6th, I conclude that this number tells us more about what the left vs right thinks qualifies as political violence, not about their support for it.
