The ongoing controversy and litigation over the Trump administration's "Muslim ban" has reignited a debate that has raged since the 9/11 attacks: Who commits more domestic terrorism-violent Salafists or traditional "right wing" extremists? According to a Government Accountability Office (GAO) report, it's the latter and by a very wide margin. From p. 4 of GAO's report:

Of the 85 violent extremist incidents that resulted in death since September 12, 2001, far right wing violent extremist groups were responsible for 62 (73 percent) while radical Islamist violent extremists were responsible for 23 (27 percent).