why do evangelical christians support ethnic cleansing?

I don't know if they do. But the fundies are extremists. And their hatred towards Catholics is very strong.

EDIT: They also hate Muslims and they are rabid supporters of Israel.

Rest of world perspective: They are seen as very deluded, often aggressively so; their beliefs are bound up with a culture that sees themselves as the 'essence' of America, while elsewhere they are perceived as the opposite. To many, America represents progress, dynamism, endeavour, innovation, excitement! It is IGY, a brave new world, a future so bright - gotta wear shades! It is common decency, understanding, compassion. It is genuine, honest and rational. It is the source and inspiration of so much positivity and good ideas. It is confident optimism. However, there is a phrase: "everything you have heard about America is true, and so is the opposite". It is a big diverse country, so opposites certainly do exist. Many evangelical fundamentalist individuals can be decent, upstanding people, who can be loyal, patriotic and friendly on an individual level. However, as a group, they are seen as being a bit backward, absolutist, aggressive and intolerant. They often only see the world through blinkered eyes, and perceive it to be full of threats and enemies instead of friends and opportunities. They latch onto outdated beliefs, and maintain them aggressively, quick to label anyone who disagrees as 'unpatriotic', 'immoral' or even 'liberal' (the last often a compliment elsewhere). They hold certain strong beliefs, and are intolerant to any alternatives. They are insecure pessimists. They resemble the kind of people that dominated the old, bad Europe, that modern Europeans have been successfully evolving away from. They seem to be at odds with many of the founding ideals of the USA; of justice, liberty, progress, accountability and freedom. They more represent the unaccountable, harsh, uncaring rulers that caused the 1776 rebellion in the first place. They represent the North American equivalent of the old Afrikaaner 'laager mentality'. They are not pro-freedom. Don't get me wrong, the USA is a beacon in so many ways, and is understandably a land of opportunity that many people strive to attain. However, it is not the attitudes of the fundamentalists that attracts them, but which more represents the attitudes that they are striving to escape. Every country has its equivalents. Conversely, it is the bright, progressive optimists and their ways that attract them to the USA. I stress that by no means all fundamentalists can be described thus, but there is certainly a distinct 'group' that can be so identified.

I do not support ethnic cleansing. Nor would I ever! God gave us the right to be here! There is no such thing as "ethnic cleansing" in my opinion. I think all human races are what God intended and all of them are supposed to be here! To wipe away any group of people is just plain old murder! Murder is a BIG sin! I hope this helps!

Perhaps you might want to mention the particular ethnic cleansing your talking about I will probably agree with you on the fundies supporting ethnic cleansing and worse crimes just like the god they serve.

they don't support ethnic cleansing. the cleansing Christians believe in is when Jesus takes your sins away when you accept Him into your life.

I do not support ethnic cleansing, that includes the babies of the womb.

No Christian would ever support ethnic cleansing

Evangelicals don't support genocide of Muslims.

If they are real Christians, they don't support it. If they are brainwashed by rabid TV preachers, then they support it, because they are brainwashed.

Do they? Please explain your question and tell us where and in what form this is taking place.