Ambrose2007: To a degree. The thing is we've all had many experiences that are relevant to its claims. For instance, I've had days where all that was in my head were miserable thoughts and worries - and GOOD things happened to me, in contradiction to this so-called law. And I've had times where I had mainly positive thoughts and expectations, and they didn't bear fruit. My provisional conclusion is that there exists no ability of our minds to materially affect reality, except through physical actions. If we could actually make reality bend to our wishes in this solipsistic sense, that would allow contradictory outcomes as (for instance) different people envision the same events (an example being the aforementioned "Bachelor" where 25 women who believed in practicing LOA wanted the same thing. Who wins?).
That being said, one might gain a lot by employing some of the (less mystical) aspects of the Law of Attraction - for example, being aware of the negative effects of our negative thoughts (how self-defeating prophecies can often become reality), and the power of positive thinking.
The Mind pays no attention to the judgment of good or bad. It is within our free will to (better)

make that choice. The Mind just produces what we focus on intensely. If it is
a passing thought or wish then it most likely won't come about.
If one puts more thought into it and plans, believes, writes
our desires down and continues it in the Mind there could be
a likelihood of it materializing. We then, let it go, believing
it to be already a part of who we are. Like a seed we nurture
it for a while to get it going but then we don't keep going back
to the seed until it gets dug up and destroyed. We have to let
it go and grow.