But now that I've read it, it does leave open a number of questions to be answered - some of them relatively easily answerable, others will probably remain unanswered to the general public but maybe not to Congress. Such as:
Was there other relevant information used for the FISA application against Carter Page? How large a role would the Steele dossier on its own have played in the approval? The memo says 'an essential part' but that's not exactly specific.
How much detail is usually submitted in FISA applications about the provenance of the information used?
How realistic is the memo's noble notion that FISA applications 'should include information potentially favorable to the target of the FISA application that is known to the government'? Does the FBI really make a habit of being so generous towards people they want to spy on, knowing that the whole application process is secret and their target won't find out anyway? Pretty important question which might also make a big difference to how people feel about the FISA process in general...
If this FISA application targeting Carter Page was done merely to discredit Trump by a biased FBI, how is it that it was renewed multiple times under president Trump, with Trump appointees Dana Boente and Rod Rosenstein, as per the memo, signing the requests for renewal on behalf of the DoJ?
The Mother Jones article of October 30th 2016, which as per the memo first revealed to the general public that Steele was a source for the FBI, also correctly mentions that the financing of his dossier 'switched to a source allied with the Democrats'. Even if we accept that the original FISA approval of October 21st was made by people who didn't possess that information, and if we accept that they would have ruled differently if they had possessed it, still it's clear that as from October 30th, the financing point was publicly available knowledge. Yet the FISA approval was renewed 3 more times. Why is that, were the judges approving it really so clueless?
The memo notes that Steele was 'a longtime FBI source' at the time he worked on the dossier, and that the DNC/Clinton campaign funded this research via a law firm. It does not say, and having searched a bit around I also don't see this anywhere else, that when Steele passed his dossier to the FBI, he had any instruction to do so from Clinton, the DNC or the law firm. Some sources explicitly say the opposite, that he decided to send his information to the FBI on his own volition. Is there any proof that Clinton or the DNC did in fact direct him to do so?
The DNC and Clinton campaign were funding opposition research, like everybody does in American politics. As shown above, them being linked to this particular opposition research dossier was public knowledge since at least October 30th 2016, before the election, we didn't need this memo for that. The memo doesn't actually show them doing anything beyond that, as far as I can see.
Don't get me wrong, the memo does certainly raise questions about the FBI's FISA application into Page and more generally their investigation into Trump's links with Russia, and I do think that those questions would need to be answered in a satisfactory way (although those answers may not be as easy to declassify as the memo itself). I might add that even liberals might appreciate the opportunity to critically review the whole FISA process. But the memo doesn't actually answer too many questions by itself.