I would have thought that was self explanatory In this context people like the person on the Left. The people who say these things - it kinda defines them.
Note I use the term Leftist more to describe a personality type, holding Left wing views does not of it's own make them a Leftist/Leftie, if they are capable of discussion without resorting to name calling/tactics/shoutdowns they are merely on the Left of the spectrum.
While I'm here, can you define the Far Right?