What is the meaning of "so that" in this context?

Question

This is a part of a book by Thomas Sowell called "Black Rednecks And White Liberals"

In Illinois during this same era, legal restrictions on access to public accommodations for blacks were removed from the law, even though there were not enough black voters at the time to influence public policy, so that this represented changes in white public opinion

This is a definition I found for "so that"

2. To such a strong degree or extent (of some quality or characteristic) that something happens or is the case as a result. Used with an adjective between "so" and "that." The vegetable is quite nutritious, but it's so pungent that many people refuse to eat it. I was waiting so long that I ended up falling asleep.

The problem is that it says "Used with an adjective between "so" and "that" and in the example, from the book it isn't

Is this the correct meaning?

Answer 1

Collins shows another definition:

so that
in British English
_CONJUNCTION

used to introduce a clause of purpose
another name for in order that

It is always tempting for politicians to ease the requirements of exams so that standards seem to improve.

Your example sentence isn't particularly well written. It isn't entirely clear if it was intended to mean

... even though there were not enough black voters at the time to influence public policy, in order that changes in white public opinion were represented.

or whether it means this

even though there were not enough black voters at the time to influence public policy, so that this [change in the law] represented changes in white public opinion

because the law could not have been voted through by black people.