The left has not been calling for one thing only. They want to delay the confirmation, on the gamble that senate and congress ratios change. That's all it's about.
The people I have known in the FBI are pretty outstanding.
There's a corollary to Occim's razor. Make the hypothesis as simple as possible, but no simpler than the facts actually demand.
You can't ignore the hyper politicized environment. It is what it is.
Well, that's what the FBI is supposed to do - facts.
If Democrats were gambling - Republicans could (and should) have called their bluff long ago and saved themselves some time. There was no point delaying the FBI investigation. But even in the worst case they still have 3 months. It would take a series of monumental fuckups for Republicans to lose that SCOTUS seat.