According to Thagard, difficulty of demarcation problem can be pass over by focusing pseudiscientist. He proposes:
A theory or discipline which purports to be scientific is pseudoscientific if and only if:
1) it has been less progressive than alternative theories over a long period of time, and faces many unsolved problems; but
2) the community of practitioners makes little attempt to develop the theory towards solutions of the problems, shows no concern for attempts to evaluate the theory in relation to others, and is selective in considering confirmations and disconfirmations. (1978)
Thagard, P. R. (1978). Why Astrology is a Pseudoscience. PSA: Proceedings of the Biennial Meeting of the Philosophy of Science Association, 1978, 223–234.