How cryptocurrency became a powerful force in Washington

In an effort to find a middle ground, the administration and Sens. Rob and Mark R. Warner (D-Va.) proposed exempting only one category of cryptocurrency miners, but under intense industry blowback agreed on Saturday to broaden their proposal to include another substantial category of mining. But those concessions did not, as of Saturday afternoon, appear likely to satisfy Wyden, Lummis and Toomey, who want much broader exemptions.