Mueller was granted extraordinarily broad authority and scope. Not just Russian connections (or not). I’d like to know WHY he was selected especially knowing his close friendship with Comey.
Hopefully, the text of appointment letter:
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"Mueller's assignment, detailed in a one-page order signed by Rosenstein, covers the federal investigation into possible links or coordination between Russia and associates of the Trump campaign but also "any matters that arose or may arise directly" from the probe. It would also extend to any allegations of perjury, witness intimidation or obstruction of justice uncovered during the course of the investigation.
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To me that means if Mueller is privy to DNC intimidation of Trump for any reason especially being accused of being a Russian sympathiser they can then investigate. If it leads to Seth Rich so be it.
Seems to me Mueller will have to investigate who actually did the hacking of DNC computers was it the Russians or someone else and if they discover the real reason the DNC is dead.
This will be a self-inflicted wound by the DNC or whomever made up the Trump colludes with Russia op.