This appears to be the line in the sand many that many of the extreme right are hoping to draw both sides of the pond.
Xenophobia
Fear and hatred of strangers or foreigners or of anything that is strange or foreign
Racism
The belief that all members of each race possess characteristics, abilities, or qualities specific to that race, especially so as to distinguish it as inferior or superior to another race or races:
The crux of the matter comes to deciding whether to fear and or hate someone before you have actually interacted with them.
It's the same as how did you decide that Obama wasn't American? What clues did you use to determine possible point of origin?
I suppose you could talk to them before they scare the bejebus. out of you with their accent. Those dastardly foreigners dress just like us.
So to be on the safe side what is one to do, how does one determine whether someone is like us or not just by looking at them. Hmmmm. Look that is not fair we just hate Johnny foreigner for taking our jobs/women/men/money/air, there is nothing racist about it.
Xenophobia and racism start from the same place, fear.
Look if all immigrants were just like us there wouldn't be a problem, and by just like us you mean what exactly; unhinged morons clasping a gun in abject terror or President Obama? A violent drunk in a pub or a highly trained cellist from China? Please define, just like us.
Look there are just too many foreigner over here taking our jobs, which ones, cleaning the toilet bowl or playing the cello?
My partner who is french has been told to go home, yet I, not being French, have never been told do do so. I wonder what the difference could be? Gender? The same so that one is out. Education? About equivalent, so that one is cleared. Religion? She is a catholic and I'm a Buddhist, so I lose one brownie point for that one. Oh, What can it be? Wait! Ah, the color of the skin, yes, that one is noticeable.
You know it is a fine line to draw to pardon someone of racism by being merely xenophobic, the problem comes when the reality of both is observed.