Based on the question Jay asked, he described his answer
rather well:
As long as your belief applies to *all* immigrants it is not racism, though it could still be an irrational bias.
Is there a word for somebody biased against immigrants, no matter what their race is?
Xenophobe is overly broad, but I couldn't think of anything closer.
On this issue, I think what you are describing is an immigration culture and not a liberal culture. When the sanctuary came back as an issue the 80's, it was an issue the liberals supported. Now days, a liberal is just as likely to support the labor side of the issue and support immigration reform that limits new immigration and supports supports enforcement.
Conservatives who are pro-business tend to support open borders as a supply of labor that will work hard, will continue to do the work others give up on and happens to be cheap. They also aren't very supportive of laws to increase corp. accountability in hiring illegal aliens.
Using immigration laws to as a tool in the fight against gang violence is something everyone should support, but seem to be afraid of the issue because they don't want to lose a large chunk of the electorate. Labeling it a liberal issue doesn't help anything.
As to the racism issue, I am not sure what I read into Ashton's comment; it doesn't seem to fit his other comments. But, he can defend himself well enough.