** "it is imperative that the department does not march backwards on its responsibilities to the energy sector and the protection of our critical infrastructure given the persistent, growing, and significant threat cyberattacks pose to our nation's economy and national security." additional signers of the letter include chairman and ranking member of the senate energy and natural resources committee, joe manchin ( .) and john barrasso (r-wyo.), and u.s. senators mike crapo (r-idaho), maria cantwell (d-wash.), susan collins (r-maine), martin heinrich (d-n.m), bill cassidy (r-la.), lisa murkowski (r-alaska), and ben sasse (r-neb.). 