We don't know anything about the shooter yet, but its natural to assume he's left of center. A lot of those on the left are gleefully owning it, or at least playing it off as Kirk deserved it. When this happens on the right, I think we usually condemn them as the crazy person they are.
One reason I think Americans need to "take a knee" is the above. When a person dies at the hand of another, 99.9whatever...% of them didn't deserve that end. When you take a political figure, elected or otherwise, the number above becomes much, much larger. Think worst of the worst, historical figures.
Now take a Kirk or similar. If you're happy that person was killed, that's kind of sick but people are kind of sick. You want to be glad they are gone, fine, whatever.
But not like this. Not at the hands of another over their political beliefs. The death of Charlie Kirk or similar on either side of an issue should horrify us, not because of the person, but because of the method. Assassinations are how wars start, they practically force people to take sides, they radicalize some and embolden others.
If (royal) you aren't outraged that a person was killed over their political beliefs, you (again, royal) are a trashtastic human being and I have no use for you as a person. That a man was killed over his beliefs, over the very cornerstone of our country (freedom of speech) is a stain upon this country and should be treated as such.