A federal special counsel and several congressional panels are investigating allegations by U.S. intelligence agencies that Russia meddled in the 2016 U.S. presidential election and potential connections between Russian officials and the Trump campaign.
Moscow has denied any interference and the president has denied any collusion.
The last person to hold a similar position to Cobb's was lawyer Emmet Flood, who worked in the George W. Bush administration to respond to Congressional inquiries.
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