Instapundit: "For Fear Of Rioting By Noncitizen Immigrants"

Glenn Reynolds writes:

TEN YEARS AGO ON INSTAPUNDIT:

I would add that the biggest evidence of a European immigration problem is that European politicians have been afraid to take some actions for fear of rioting by noncitizen immigrants. When your foreign and domestic policy are hostage to people who aren’t your voters, you’ve got a problem.

Reynolds is writing about the conflict between Invade the World and Invite the World, seen more recently in vile Muslim abuse of returned British soldiers--see Britain: Muslim Fifth Column Insults Returning Troops, by Brenda Walker,  also  Immigration Brings the War Home to Britain.

What actions would the American government be afraid to take for fear of "rioting by noncitizen immigrants"? Possibly serious immigration enforcement.