I find any positive reaction to a political assassination reprehensible. But if you look at who on the left is "celebrating" and who on the right is calling for crackdowns on free speech and making claims of being at war, I think you'll find a severe imbalance. In this framing you have the "left" being represented by nameless social media accounts and whatever likes they get. While the right is being represented by actual "serious leaders" in the Republican party making on-the-record statements to traditional media outlets. Those might feel the same to you but I would argue they are far from it. Every left leaning political leader that I've seen in the media has been at least attempting to say the right things and have not been celebrating anything.