The saying goes that my right to swing my arms ends where your face begins.
Equally the student unions right to decide what they personally listen too ends when they prevent others that want to hear the speaker from listening.
At that point they are infringing on another's right to free speech.
In the case of the student unions it is an inherently political organisation using their power to restrict the rights of what I can only assume is a minority of the student body.
Edit - formatting
Are you seriously suggesting a students speech should be curtailed because they are in a minority! (Or a majority for that matter). You are either trolling, or you are part of the problem.
If I don't want to listen to somebodies ideas (or read their books), I will make that decision thakyou. Not the students union!
What is is about "I disprove of what you say but will defend to the death your right to say it" that YOU do not understand?
Our UK students unions are repeatedly preventing people speaking on campuses because they object to their views [1]. This IS 'cancel culture' and it is not healthy for our democracy.
Whatever happend to "I disprove of what you say, but will defend to the death your right to say it" ?
[1] https://www.thetimes.co.uk/article/how-is-cancel-culture-aff...