First, let me say that while I do not think the Comey Letter ever put Clinton in real danger of losing the election, I think or rather fear that it may already have lost the Democrats the Senate. I'm not saying they have lost the Senate or that they can't win. They might still win it. But it was always a much closer run thing than the top of the ticket. The consequences of that difference are great.
Second, the political consequences are why this was wrong. Neither party has a right to control the Senate. The point is that this letter, this entire imbroglio never should have happened. It defies tradition, explicit DOJ guidelines and respect for elementary democratic traditions. It was not a close call. This is why most legal experts and former DOJ officials on both sides of the aisle said so. The second letter is nice. It doesn't change the gravity of the original error or the damage already done.
Third, if you looked closely at the apparent nature of what was discovered, the reasoning of the July decision and the nature of the relevant law, it was always extremely unlikely that these emails would change anything, extremely unlikely. As I'm writing, news is emerging that virtually all the emails were simply duplicates of the emails already reviewed by the FBI or personal emails of no public consequence. In other words, not only was nothing found to change the original judgment, at a basic level there actually was not even any new evidence to review.
This should never have happened. It was inexcusable. It was driven by politics. It never should have happened.