Extra emphasis here: There were fewer than 150 successful denaturalizations in 50 years. Only 11 were even filed per year from 1990 to 2017, before the Trump-era.

The DOJ putting out 123 cases in 18 months is a massive escalation. The reason it isn't thousands is due to the constraints of the existing law. In 1967, 1980 and 2017, SCOTUS ruled to restrict denaturalization authority, and no prior admin has tried to undo that. Trump I and Trump II are trying to make it common.