I figure this has been debunked as am "incorrect narrative".
For example this site called MotherJones
US Mass Shootings, 1982-2017: Data From Mother Jones’ Investigation – Mother Jones keeps an account of mass shootings.
Even if they count Abdelkrim Belackheb (born in Morroco) or John Zawahri (of Lebanese descent) as whites, and omit "shootings stemming from more conventional crimes such as armed robbery or gang violence". Which of course skews the stats against the whites.
Whites are still underrepresented with regards to their share in the population.
Now limit that to the Jihadi attacks only and their share in the population and you get the picture (also think of the plots that were successfully prevented).