Leftists are evil and spiteful. They don't care that this is going to hurt them in the long term. They don't care how bad they look. They don't care about losing popularity. They just see someone they don't like is dead and they celebrate. They're far too short-sighted to recognize any consequences of this.
If you thought America is turning right too much , it's only going to get worse. When you show the nation how blood thirty and evil you are, you turn everyone against you.
Nobody believes the democrat's "we believe in basic human empathy" shit anymore.Remember the attempted assassination of Trump? It was horrible for the left and a major reason why he won the election. This assassination being successful is worse for the left, it only angers everyone so much more.
If you're smart, you don't create martyrs. History has told us countless times that when you create a martyr, you only boost the morale and dedication of the people on his side, the left has created a million more Charlie Kirks and radicalized everyone to the right even more.