Why domestic terrorism is hard to fight

After the attacks of Sept. 11, 2001, federal officials were given broad powers to disrupt foreign terrorist plots, but the mass shooting in El Paso over the weekend underscores how few options the authorities have at home.

After the massacre in Texas, which targeted Hispanics, President Trump promised on Monday to give the authorities “whatever they need.” The motive for the weekend’s second attack, in Dayton, Ohio, remains unknown.

The challenges include the fact that no government agency is responsible for designating domestic terrorism organizations, and that the First Amendment makes stopping terrorist acts before they happen more difficult. Focusing on white-supremacist violence would also test whether Americans are as accepting of aggressive law enforcement tactics when the suspects aren’t Muslims.

Yesterday: Mr. Trump called on the country to “condemn racism, bigotry and white supremacy” but did not endorse gun control measures. He connected the attacks, which killed a total of 31 people, to mental illness, video games and “the perils of the internet and social media.”