I believe that the apparent intolerance shown toward “illegal immigrants” is that everyone who reaches these shores through a creative route is classed as illegal. We are encouraged to think this way by aspects of the media. But the term covers many types of potential immigrant. I'm thinking here, refugee, asylum seekers, people outstaying or misusing their legally obtained visa , the economic migrant hoping to slip quietly into the country.
I'm sure there are more descriptions. But they all become “illegal immigrants” to all forms of media and viewed in the same negative way because of the lack of clarity. While we should be welcoming to some and understanding of difficulties , we should perhaps be cautious of the motivations of others.