The text of the announcement of the House Judiciary Committee hearings on “White Nationalism” includes this:
Last Congress, Democrats in Congress sent letters to the Administration to demand answers about hate crimes, the targeted surveillance of minority communities, and the growing threat of white supremacy and right wing extremism. To date, the Administration has provided little or no substantive response to these requests.
On February 22, 2017, Representative Stephanie Murphy and 150 Members of Congress sent a letter to Attorney General Jeff Sessions, Secretary John Kelly, and FBI Director James Comey, urging federal agencies to address threats to Jewish organizations.
But everybody knows those threats (which were simply phone calls, seriously illegal, but representing no actual danger) were exposed as Hate Hoaxes months ago.
Use of the term "false flag" by the MSM is an attempt to tie Trump to really weird conspiracy theories, but the older espionage version of the term is equivalent to what we call a Hate Hoax—faking a racist attack or threat and blaming it on whites. That's what happened to Jewish Community Centers in 2017.
Two people have gone to jail over these threats. One was a black journalist (Juan Thompson) who faked the hate to blame his white ex-girlfriend. See "Nothing to See Here, Please Disperse:" How the NYT Downplays the Juan Thompson Hate Hoax Fiasco.
The other was an Israeli teen (Michael Ron David Kadar) who did these robo-call threats to Jewish Community Centers to attract headlines, recognizing that targeting Jewish centers would receive the most headlines.
The WikiPedia entry on these threats is pretty good.
By the way, the committee claims that the Attorney General and FBI Director failed to answer this letter signed by 150 members of Congress, but they did catch these guys. They're both in jail. (Kadar in Israel, they wouldn't extradite him.) So what we're dealing with is not "white nationalist" hate crimes, but anti-white nationalist hate hoaxes. And that's only one of the discredited claims in the Committee's Press Release.