Political Correctness Gone Mad?

‘Without free speech there is no true thought.' -Jordan Peterson

‘You're telling me I'm being sensitive, and students looking for safe spaces that they're being hypersensitive. If you're white, this country is one giant safe space.' -Michael Eric Dyson

Is political correctness an enemy of free speech, open debate and the free exchange of ideas? Or is it a progressive force, eroding the dominant power relationships and social norms that exclude marginalised groups from society?