I like your question. I don't know why someone voted it down, though it might be better for legal than political. The opening question "is it dead" is too broad but you make it nice and specific here:
it seems fair to ask whether or not attorney-client privilege has been
handled in a consistent and impartial manner in the Trump and Hillary
I hate to answer a question like this as I'm a legal-noob, but this USA-today article seems to address your question pretty well.
As noted in some of the answers above, attorney-client privilege doesn't apply if the client and the attorney conspire to break a law.
"How would they know" - fair question.
"How do they avoid obtaining privileged and protected information?" - also a fair question.
The article points out that warrants (as opposed to subpoenas) are issued if there is fear that documents will be destroyed. It's rarely done that a warrant is issued for a law office, but if a federal judge OK's it, it's legal.
it's very unusual for the Department of Justice to permit prosecutors
to raid an attorney’s office and that’s because you want to be careful
not to get privileged material," said Litman, who teaches at the UCLA
School of Law and continues to practice at the law firm Constantine
"In order to get the OK to raid Cohen's office, prosecutors would have
had to get approval from high up — in this case from Deputy Attorney
General Rod Rosenstein — and demonstrate to a federal magistrate both
probable cause and the need for a warrant instead of a subpoena (such
as a concern that Cohen might destroy evidence), Litman explained."
In addition, the probable cause would have to relate to a crime
centered on Cohen, not Trump or someone else. "You can’t use it as end
run around to get to the client," Litman said.
So, in short, if they think a lawyer has broken the law, and they have sufficient evidence to get a warrant and they believe that lawyer might destroy his records, then it's perfectly legal to investigate that lawyer.
"But, OK, so the lawyer broke the law, what about all the stuff the client told the lawyer that was privileged?"
All of that's still privileged. What's not privileged is when the client and the lawyer conspire to break the law together.
from the article:
There will also be a "taint team" to examine everything before it is
handed over to prosecutors to make sure that those conducting the case
never see any material that might be "tainted" by attorney-client
The only way the prosecution would be permitted to examine any
material that might otherwise fall under the attorney-client umbrella
is if it is determined to be part of a crime jointly undertaken by the
attorney and the client. But for the privilege to be nullified under
the "crime-fraud exception," Litman said the taint team would have to
get the approval of the court before the material could be presented
to the prosecution.
I used to work in investment banking and we had something called a wall, between those who had inside information (investment bankers) and those who didn't (traders/debt/equity floors and research). There's something like that here, where the people who read what they find in Cohen's office, pick out what they think falls outside of attorney client privilege, give that to a judge, who, if it meets approval, then and only then, Team-Mueller gets to read it.
As far as I can see, it's all legal, all straight up and in no way a violation of attorney-client privilege. Now, if documents are slipped under the wall - so to speak, that would be a violation. If deputy attorney general Rod Rosenstein did this as a favor to Mueller, not because the warrent was warrented, that would arguably be a witch hunt, but if the wall was respected, not a violation of attorney-client privilege.
And if stuff is leaked that should be kept private, that's unethical and a smear campaign. But my understanding, as long as the warrant was offered based on good evidence and in good faith and as long as the wall is maintained, then attorney-client privilege was in no way violated.
I find your point on Hillary interesting, because, despite all the talk, James Comey concluded his investigation fairly quickly. Guilty by association is different than violation of attorney client privilege. I think, in both Trump and Hillary's cases, there's a lot of "He's guilty/she's guilty" before the verdict is in. I don't know enough about the various Hillary situations to know if attorney-client privilege ever came up. In Trump's case, as he said it in direct response to the Warrant and "Raid" on Cohen's office just a couple days ago, it's much easier to pin-down.
All this is basically what AGC said. I'm not sure I added anything other than quoting a different article. I think he gave a good answer.