It is outrageous to demand the identity of any whistleblower. Knowing the identity of the whistleblower serves no purpose. If a whistleblower comes and whispers in my ears that my wife was having an affair with Donald Trump I will confront my wife with that info. She will have to deny or admit. That should be the end of the matter. And if she denies and I find an orangutan hair on her blouse I will query again. Unless she suspects me having an affair and feels that another woman setting up the friction there is no need for her to know the identity of the whistleblower.
In the case of the DJT , either he denies making a telephone call to Ukraine President or disputes the content of the call it would be premature to know the identity of the whistleblower. If there are no grounds for any allegations then there is some justification for knowing the identity. We have solid proof for the calls. We have solid evidence for the content of the conversation. Further we have evidence for moving the evidence to a secret server.
If someone says it is going to rain therefore take all the washings in. You hear the thunderstorm and feel the drizzle, how important to know who predicted the rain before taking the washings in?
So, the actus reus and the mens rea are proven and know the full details of the offender. As the comedian Bill Maher described, are we waiting for the Dog the Bounty Hunter to come to put the hand cuffs on Donald John Trump of 1600 Pennsylvania Avenue NW in Washington, D.C?
Historically , shooting the messenger has been the norm in dictatorial regimes therefore it should come as no surprise if the present occupants of the Whitehouse demand to know the identity of the whistleblower (who I hope and pray to be any one amongst Melania, Baron, Ivanka, Jared, Do(umb)nald-Jr, Eric the Bright, Sean Hannity, Kellyanne Conway, Sara Sanders or one of his trusted body guards or even Rupert Murdoch)