Rafidhis, Nasibis and Kharijites all are misguided, people of innovation and takfir. They all caused division among ummah and separated from Ahlul Sunnah wal Jamah.
The term Ahlul Sunnah Wal Jamah means following the Sunnah of Prophet which is derived only from authentic narrations and to be with the majority (Jamah). Majority means those who are on path of majority of sahabah, tabi'in and taba tabi'in (First 300 hijrah years).
Maula Ali a.s says in Nahjul Balagha sermon 127,
With regard to me, two categories of people will be ruined, namely he who loves me too much and the love takes him away from rightfulness, and he who hates me too much and the hatred takes him away from rightfulness.
The best man with regard to me is he who is on the middle course. So be with him and be with the great majority (of Muslims) because Allah's hand (of protection) is on keeping unity. You should beware of division because the one isolated from the group is (a prey) to Satan just as the one isolated from the flock of sheep is (a prey) to the wolf.
Comment: And the great majority of muslims during the time of Maula Ali a.s were those who loved and befriended Abu Bakr a.s and Umar a.s. We are with that majority of muslims. Majority at that time was not rafidhis, nasibis or kharijis.
What Maula Ali a.s said is in accordance with what Prophet s.a.w.w also said,
(1) "I saw the Prophet [SAW] on the Minbar addressing the people. He said: 'After me there will be many calamities and much evil behavior. Whoever you see splitting away from the Jama'ah or trying to create division among the Ummah of Muhammad [SAW], then kill him,
for the Hand of Allah is with the Jama'ah, and the Shaitan is with the one who splits away from the Ummah, running with him.'" Source:
http://www.sunnah.com/nasai/37/55(2) A man said: Messenger of Allah! It seems as if it were a farewell exhortation, so what injunction do you give us?
He then said: I enjoin you to fear Allah, and to hear and obey even if it be an Abyssinian slave, for those of you who live after me will see great disagreement.
You must then follow my sunnah and that of the rightly-guided caliphs. Hold to it and stick fast to it. Avoid novelties, for every novelty is an innovation, and every innovation is an error. Source:
http://sunnah.com/abudawud/42/12But neither every shia nor every sunni is Rafidhi, Nasibi or Khariji. Accusing anyone of such thing without proper knowledge is also misguidance.