A high-functioning-liberal, in a candid perspective, refers to an individual who identifies with some of the completely stupid liberal political beliefs and values but does not necessarily conform to stereotypes that some people associate with liberalism, such as having unconventional hair colors, being as fat as Lizzo, or taking 3-5 business days when they state their preferred pronouns.
Emily is considered a high-functioning-liberal. Despite being a staunch advocate for progressive policies and social justice causes, she preferred her natural hair color, maintained a healthy lifestyle, and didn't share her fucking pronouns.