The failure stems from an inability to define hate, but mostly it fails from the irrelevance of hate as anything other than a motivator for committing a crime.  Motive, though, belongs solely in the jury box during the punishment phase given a conviction of a crime; it should not be foreordained by a Government’s attempt to define the hate or by Government’s more evident attempts to discriminate among groups of Americans and single some out for favorable treatment at the expense of other groups of Americans.

That’s demonstrated by Illinois and Ohio law, which comes up from case of the four blacks who attacked a white disabled man and live streamed it on Facebook, as discussed by Eugene Volokh in his Washington Post article.  For instance,

The focus, then, isn’t on “hate.” For instance, if a thief selects a physically disabled victim simply because he thinks it’s less likely that the victim will fight back, that too is covered as a hate crime under Illinois law.

And

Similarly, the Amish beard-cutting case was prosecuted as a hate crime on the theory that the targets were chosen by fellow Amish perpetrators because of the targets’ dissenting religious beliefs within the Amish community.  …  Choosing someone for attack based on his religion would be a hate crime whether the motivation is hatred, theological disagreement, or whatever else.

You see the irrelevance of hate in such crimes, yet Government, in these instances Illinois’ and Ohio’s, arbitrarily tacks it on, just because.

As Volokh put it,

But the Illinois statute and the federal statute [another of his example laws], like most other hate-crime statutes that I’ve seen, focus on discriminatory selection, not the underlying emotion behind the selection.

Indeed.  I pick you for my crime victim because I think I’m more likely to get away with it than if I’d selected someone else or because I’ve decided (legitimately or not) that you’d done me wrong, and I was determined to get you back, and I do the crime.  But if you happen to belong to a government-favored group of Americans, my crime—completely unchanged in its nature or motivation—becomes much more serious solely because of Government’s own discrimination: it has chosen to favor your group over other American groups and so to discriminate against those other American groups.

Which also is an argument for doing away with Governments favoring, for any purpose, this or that group of Americans over other groups of Americans, which Government has decided should be disadvantaged by that favoring.  That’s hate crime by Government.