These institutions were started by Brougham and Birkbeck in the twenties at a time when, as a writer described it, “there still prevailed in many quarters a strong jealousy of any political discussion by the people, and still more of any society which proposed to assemble periodically several hundreds of the labouring classes”. Hence their founders, in their desire to conciliate opposition, banned political or religious discussion or books, and forbade newspapers.
How do the adverbs still + more compound to generate its meaning?