A commenter said that
the real rulers of the US and the world weren't scared of Trump for the reason you think [because he threatened the deep state]. They were scared he unintentionally would encourage a certain segment of the US population to create a third party. Not that this would have been the end of the elites/deep state, but this would have created a major headache for them, since they would need to invest resources and propaganda to this (un)expected problem.
If you’re mystified by this, you’re not alone.
I wonder what segment of the U.S. population the commenter meant. If he meant the Trump “base”, that would have been good news for the “real rulers”. They are, presumably, global elites (e.g., Klaus Schwab and the inner circle of his World Economic Forum) who are pushing economically and socially destructive policies on America and the West.
The rise of a third party consisting of the Trump “base” would cripple but not destroy the GOP. The Democrat Party — the tool of the elites in the U.S. — would then have an open road to firm control of the White House and Congress.
Perhaps the commenter will enlighten us.