here's some more comments from the DOJ - Assistant Attorney General John P. Carlin

He said he was struck by the difference in attention to two different acts of terrorism in 2011. One was the arrest of Khalid Ali-M Aldawsari, a Saudi citizen and Texas resident, who was accused of plotting to build a bomb and researching potential U.S. targets, including former president George W. Bush.
Around the same time, a man with ties to a
neo-Nazi group planted a
pipe bomb along the route of a Martin Luther King Jr. Day parade in Washington state, and his intent was to kill and maim, Carlin said. A parade worker spotted the bomb, and law enforcement officials defused it. Kevin William Harpham was sentenced to 32 years in prison.
But, said Carlin, who was senior counsel to then-FBI Director Robert S. Mueller, “the Aldawsari case got a lot more public attention.” It was discussed at National Security Council meetings. And prosecutors had a variety of legal tools they could use.
Although the Harpham case had Mueller’s “full attention” and “hundreds of FBI agents” and local law enforcement officers were on the case,
“it didn’t get as much public attention. And you didn’t have the same tools available to you.”https://www.washingtonpost.com/news/post-nation/wp/2015/10/15/how-the-justice-department-is-stepping-up-its-response-to-domestic-extremists/ 