I think politics need to be interesting for people to vote. If the expected outcome is that everything only worsens a bit, you'll never get people to vote for you. So by leaning right, she basically tried to appease the conservatives, but made progressives lose interest. I don't think that anyone (or a substancial number) on the left tried to "own" her.
Hopefully there will be next elections, and hopefully there will be a party worthy of voting for it.
(Also disclaimer, I am not american, and am just objectively stating the obvious)
I think you got it a little mixed up. The state needs to have it proven that he did in fact commit that murder, and not leave any doubt about it. It's really not his job to prove anything, let alone that you can't prove innocence in a lot of cases.