One of the areas that has held public fascination in the Larry Craig situation is the vagueness of the charges and allegations against him. Put simply - what did he actually do wrong - tapping a foot and reaching with his hand? He clearly did not break any established and obvious laws by those actions (not unless laws have become so over broad and burdensome that they've even caught me, Public Defender Dude, by surprise). So what he did had to be interpreted by a police officer as being illegal, because it is not illegal on its face.
This brings up an area that I've so often railed against - police officer opinion testimony (or, as I like to put it, "my opinion is that you're guilty."). I think that this opinion testimony, whether in the context of gangs (giving an opinion that any sundry crime was committed for the benefit of a street gang so as to make minor crimes strikes, or average crimes life sentences), or drugs (giving the opinion that whatever amount of drugs that someone possessed was obviously possessed for purposes of sale), or any other area.
Prosecutors love this stuff. It's like 2 closing arguments in their case. They get a police officer who gets to get up on the stand and essentially say "I've investigated thousands of cases, and in my opinion this person is guilty, because his case falls in with all these other ones in this manner." It is highly prejudicial, and in many cases, highly meaningless. Let's face it, any old person in the world could figure out whether a certain crime benefits a gang without having to hear a police officer point his finger at your client and say "he definitely did it for the gang." How about general testimony about how a gang may benefit, or something to that effect?
And the Larry Craig case is just like that. The police officer sees something, and interprets it one way. Larry Craig interprets it the other way. It is so difficult to get a jury to realize that a police officer sees the world in a certain manner, and everything they see falls into line in that manner. When you go out looking for gay people, suddenly everyone is gay and hitting on you. Even the most subtle actions can be taken as hitting on you.
The only way that Larry Craig could have ever been convicted in this case would have been if the officer had gotten on the stand and said "I've investigated thousands of these cases, and what Larry Craig did was hit on me and attempt to have sex with me." How do you refute that? It's very difficult.
That being said, going against that kind of testimony can be very fun, as well. You get to pose hypotheticals to the police, who have to sometimes take ridiculous positions to continue to assert your client is guilty.
I had one gang case where the gang officer's testimony won the case for me. Through cross examination, I was able to put forward a whole different scenario about how the crime took place, and ask if that would be consistent with guilt or innocence, and the officer had to concede that looking at the case in that manner it made my client not guilty (of the whole crime, not just of the gang allegation).
So, I hate these types of cases, and this testimony, but a good lawyer learns how to turn it in their favor, or at least neutralize it as much as possible.
Good luck Larry (and I mean that - they're nothing wrong with being gay!).