Being anti-illegal immigration and pro-legal immigration doesn't mean you want to flood the country with legal immigrants. That's the case in the UK, by the way, where the vast majority of immigrants are legal and it's the reason for the growing anti-immigrant attitude of the natives.
People who are anti-illegal immigration and pro-legal immigration also have requirements like:
- there should be a fixed number of legal immigrants
- they should be well vetted (this may be lacking in the US and UK)
- legal immigration should be points based
- quotas for legal immigrants should be increased contingent on the number of illegal immigrants which are expelled
- there should be checks to verify that visas are not abused (the way H1Bs are abused in the US with under qualified immigrants)
- asylum should be abolished because it's abused. It can be replaced by paying poorer countries to permanently host asylees.