My question is, does racism or hatred of another community, take you out of the fold of Islam, or is it a major sin? Can you provide some scholarly sources and opinions on this matter?
Mighty Allah says in Quran
يا أيها الذين آمنوا لا يسخر قوم من قوم عسى أن يكونوا خيرا منهم ولا نساء من نساء عسى أن يكن خيرا منهن ولا تلمزوا أنفسكم ولا تنابزوا بالألقاب بئس الاسم الفسوق بعد الإيمان ومن لم يتب فأولئك هم الظالمون
O you who have believed, let not a people ridicule [another] people; perhaps they may be better than them; nor let women ridicule [other] women; perhaps they may be better than them. And do not insult one another and do not call each other by [offensive] nicknames. Wretched is the name of disobedience after [one’s] faith. And whoever does not repent – then it is those who are the wrongdoers.
so we can conclude that it takes one to repent for this sin and it doesn't make one be out of Islam .. that's what I know and only known to Allah ..
The Prophet Muhammad (peace be upon him), during his Last Sermon in Minâ, said: “O people! Your Lord is one Lord, and you all share the same father. There is no preference for Arabs over non-Arabs, nor for non-Arabs over Arabs. Neither is their preference for white people over black people, nor for black people over white people. Preference is only through righteousness.” Then he said: “Have I conveyed the message?” and the people declared that he had. [Musnad Ahmad (22391)]
Prophet Muhammad (may Allah be pleased with him) said that there is no difference between a white person or a black person or between an Arab or a non Arab. we are all equal so yes it is haram and a sin to be racist as in Islam there are no superior or inferior races everyone is the same.