The idea is that free citizen in a democracy need to be able to read, think, analyse, and evalution information and also candidates for election.
In that way, they can make wise decisions and avoid becoming a dictatorship (an authoritarian government). Liberal education is crucial if a society is to avoid tyranny (rule by a very few people)
Until we the ability to freely obtain knowledge and form our opinion, then we can truly feel that we as a citizens had the full liberty to pursue whatever things that interest us and replace the government who wanted us to behave otherwise