Interesting question in light of Sunday's events and Trump/Vance claims since then because I think this is a question of how much and what type of rhetoric is justified or accurate.
I don't think anyone on this board is okay with a candidate or his/her campaign advocating actual violence towards the other. But neither Harris nor her campaign have said people should assassinate Trump; conversely, neither Trump nor his campaign has said people should assassinate her.
The difficulty is extrapolation of "what's ok" by the accusatory rhetoric. For example, from the perspective of the anti-Trump crowd, given the events of 1/6, it is perfectly accurate to call him a threat to democracy. Even some Republicans use that language. Does that cause a crackpot to try to assassinate him? Can you "blame" such comments, even if seemingly objectively accurate, for the assassination attempt? I can see it argue both ways.
Trump says that Harris is an extreme communist and that the country will end if she is elected. His supporters would say that's okay given their interpretation of her economic policies (we can argue over whether those perceptions are accurate; point is, the Trump allies think is it). Trump's not expressly calling for violence against her, but if some loon acts based on Trump's comments, is it his fault? Again, I can see it being argued both ways.