What if Leon Czolgosz hadn't assassinated President Mckinley?

This is rather a tricky question, in more ways than one. Leon Czolgosz was arguably the most "successful" of the four American Presidential Assassins. He was an anarchist and disciple of Emma Goldman who was ultimately deported for, among other things, supporting Czolgosz' assassination of Mckinley in her writings. The assassination of Mckinley led to the replacement of a pretty good conservative president, with a great progressive president. Thus, the result of Czolgosz' action was certainly a shift to the left in American politics, which was certainly consistent with his extreme leftest political agenda, although certainly Theodore Roosevelt wasn't going to go as far left as Goldman or Czolgosz wanted. Anarchists tend to be ambivalent about Czolgosz, on the one hand approving of the political shift to the left he caused, on the other hand disapproving of the method employed as being too brutal, of course. I suppose the question is, to what extent were Theodore Roosevelt's reforms inevitable, in any case? And, to what extent was Theodore Roosevelt very likely to be elected President, in any case, following Mckinley's second term of office? If either of these questions is answered in the affirmative, did Leon Czolgosz simply waste both his life, and a bullet?