Wait, Comey's team took over a year to review 55K Clinton emails, but took 9 days to clear through 650K?...
If they used computer search power to identify that most (or all) of the emails are copies of ones that were already reviewed in a prior investigation, many were duplicates of mails sent out to multiple individuals etc - it would then be pretty quick to conclude that there is nothing much new to see here.
Unfortunately, we are dealing with a situation where once people have decided that one side of the argument are criminals in a conspiracy, they then refuse to listen to or read any evidence to the contrary, and automatically apply much lower levels of proof required to those who they don't like. e.g. if Donald Trump is under investigation for some crime or other, it must be a false allegation, whereas if Hilary Clinton is under investigation, it must be true.
Unfortunately there have been plenty of psychological studies that show that once a person takes a very strong stance on one or other side of an argument (especially if it's a public stance), their brain will then automatically, and subconsciously, look to filter out or ignore evidence that contradicts their position. Even highly educated people who are aware of this fact already will still all prey to it to some extent. If you are unaware of this, or decide not to believe that it's true, it's very strong, as evidenced by recent debates on these threads and everywhere else.
This is more than just confirmation bias - it's the active ignoring of clear evidence and data that supports the the opposite conclusion.
In a scientific situation, the solution to this is apply the scientific method. In a legal situation, the solution is checks and balances designed to establish the facts to some level of standard, like "beyond reasonable doubt".
In a political situation, unfortunately candidates are not required to prove to any reasonable standard that what they are saying is true. Further, media outlets of all kinds cannot be relied upon to communicate the information correctly in a balanced way.
Finally, due to the internet and massive numbers of TV channels targeted at specific demographics we now live in a time when it's very easy, and even encouraged, for people to surround themselves with a bubble of "news" which is all heavily biased towards items which confirm their own opinion.
On a separate point, and this is not a moderation comment just my personal comment, can I suggest that if posters here are going to post links to articles on other sites that they believe supports their viewpoint, can you please read the article you are linking to first. I've seen several cases on recent pages in this thread where links were posted to support a point, but when I clicked and read the link, it didn't support the point at all, and in at least one case it said the complete opposite. To everyone else, please don't assume that because someone put a link in their post, it must be true.