First, SPLC is a joke. But lets address it, even if it's a joke. It states in the NPR article you linked... a 30% increase in hate crimes over the last 4 years, 7% in 2018 alone. It also incorrectly references the hate crimes statistics from the FBI as 17%. On the SPLC website, it states a 50% increase in the last year and that 40 people have been killed by "radical right terrorist attacks in 2018" (
https://www.splcenter.org/hate-map). None of these have statistics behind them that back up any of those claims, can you point me to them?
The NYT article you linked, also references SPLC. See above. Add to that, it references the same talking points, without any data behind it. "The law center said the number of hate groups rose by 7 percent last year to 1,020, a 30 percent jump from 2014.". It also erroneously states "That broadly echoes other worrying developments, including a 30 percent increase in the number of hate crimes reported to the F.B.I. from 2015 through 2017 and a surge of right-wing violence that the Anti-Defamation League said had killed at least 50 people in 2018." I say erroneously because 1) it doesn't mention the 2015-2017 data points don't discuss the +1000 additional reporting agencies, or that the hate crimes the FBI reports on are all hate crimes. Someone before me summed this up nicely earlier in this thread. 2) it doesn't even match it's own website 50 people in 2018? Their website says 40 (again without anything to back up that figure other than... themselves saying it's 40 (or 50 per the NYT quoting them).
The third article, from SPLC itself, again is quoting it's own data, and falsely reporting the hate crime statistics but this "article" is quoted in the above two articles. So really, you are referencing everything from the SPLC so far.
Now the 4th article, is well thought out and from an unbiased news agency. It states several things about the things above.
"
Experts, however, caution that the FBI’s hate crime statistics are an imperfect way to track the rise of white nationalism. Not all of the hate crimes overall were committed by white nationalists (some of the documented incidents, for example, were anti-white). The data do not identify the perpetrators that way."
"
There was also an increase in the number of agencies participating in reporting hate crimes to the FBI and a subsequent increase in the population covered of 5.7 percent between 2016and 2017. So some of the increase is likely tied to that alone."
"Beirich said there is a lot of evidence pointing to a rising threat from white nationalism, but, she said, “I’m not sure FBI hate crime statistics prove the point.” She notes that a Department of Justice crime victimization survey in 2015 found “U.S. residents experienced an average of 250,000 hate crime victimizations each year from 2004 to 2015.” But the survey does not show trends over time, Beirich said." (Note that Beirich works for SLPC)
All the above aside, you don't actually have a number of US based white supremacists, because there isn't one reported anywhere. The telling statistics, are from the FBI hate crimes website, and methodology has changed significantly from 15-17. I agree hate crimes are up, but I'd also say it's all hate crimes, which none of those articles do a good job of calling out. There are hate crimes significantly increased more than others there. The FBI statistics alone tell a very different story than "white nationalism is on the rise".