Should Chinese people not be allowed to celebrate their own customs? Tell me, what American holidays are there exactly that have been done away with in order to accomodate immigrants?
Maybe you should stop celebrating Halloween and St. Patrick's Day in the USA, since you stole them from us and raped all meaning from them.
Deporting legal immigrants is an infringement of their rights. They probably pay their taxes like any other good citizen, which is probably more beneficial to the Mexican economy than Americans flooding in every year as tourists and reducing it to a service-based economy where local culture is bastardised for the sake of tourist dollars.
I would suggest that your's is the attitude of a person who doesn't really know what his own culture is, what defines it, and thus you are paranoid of those who have a defined culture. I see it all the time in Northern Ireland. The culture of those who see themselves as British is massively paranoid of the Irish identity because the only defining quality the British have here is that they are not Irish, and thus they can only celebrate the subjugation of Irish people.
Ironically, they complain about their own culture being under threat from the one they would wish to destroy.
I put it to you that your only personal cultural identity lies in trampling down other cultures, as has been the defining aspect of white, Anglo-Saxon colonisation of the Americas.