The website https://81m.org/ has developed a tool to periodically check the latest videos uploaded to the Official White House YouTube channel using YouTube's API, and counts the increases of likes/dislikes. It then observes for any decreases in dislikes, and calculates a "Manipulation amount" percentage per video, based on the number of dislikes removed compared to the original increases.
The website claims that other channels such as PewDiePie have no manipulation, and their running dislike count is identical to the reported numbers on YouTube. However, on White House videos, the page displays manipulation amounts on videos ranging from a few dozen percent, to several thousand percent.
As discussed in the question Does YouTube delete video dislikes?, YouTube occasionally removes both likes and dislikes, and claims that it is to combat fraudulent activity or click farms.
Is there any information why YouTube is doing so on this channel, and especially to the scale that it's happening?