I guess the sarcasm was not obvious.

I was mocking what will presumably be a Republican talking point as a 15 dollar donation is immensely inconsequential.

I agree with you that party registration is basically meaningless for a 20 year old who seems to have not even ever voted, nor has any as of yet evidenced strong political beliefs voiced privately or publicly.

As of right now, the shooter does not seem to have been very politically involved either way and is being portrayed as basically socially awkward and picked on in high school.

If the person had a long history of political involvement either way or had published a manifesto or something like that, that may be worth discussing, but so far there is nothing to indicate any kind of strong ideological motive, more along the lines of 'troubled young adult has nothing to live for, decides to try and become famous and/or die trying.'