Cryptocurrency and blockchain enthusiasts were excited about the ​announcement​ this week that President Donald Trump plans to name Office of Management and Budget Director Mick Mulvaney, a longtime supporter of cryptocurrencies and blockchain technology, as his interim White House chief of staff before the end of the year. As a congressman, Mulvaney was a co-founder of the ​Congressional Blockchain Caucus​. When it comes to actually embracing cryptocurrencies, the U.S. has been generally skeptical. As a recent opinion piece in the ​Harvard Business Review​ by law firm Jones Day blockchain initiative leaders Stephen J. Obie and Mark W. Rasmussen noted: ​“Without clear regulations, cryptocurrency innovation in the United States is being stifled.…