Capitol Hill discussion about the electric grid is shifting to physical security, leading federal officials and some lawmakers to worry that focus on cybersecurity is waning.

Lawmakers such as Senate Majority Leader Harry Reid, D-Nev., and Senate Intelligence Committee Chairwoman Dianne Feinstein, D-Calif., have given increasing attention to physical grid security following an April 2013 attack at a San Jose, Calif.-area transmission substation by armed gunmen.