Penalizing the President (The difference between illegal and unacceptable)

Interesting read, and makes a good general point. I have trouble with the aspect that it seems to insinuate that only one side is making, what appear to be, claims sans-evidence which instigate investigations which may prove to be wasteful and fruitless.

Unlike the example provided, the one sure casualty of all that's happening is transparency. The political obfuscation cloud spins faster than a hurricane. Thus each side will become more entrenched in their beliefs on the matter.

How can you know an investigation will be fruitless until it is conducted? If Alice trusts Bob, but Eve doesn't, what do we do? Would the investigation into Bob be fruitless or not? Isn't that what the Federal Bureau of Investigation is for? To investigate all claims of impropriety equally and fairly? We accept the false negatives because the cost of giving the benefit of the doubt blindly is a dangerous proposition.