The best solution to the immigration problem is to make immigration officials, sponsors, politicians, etc., any one who helps bring immigrants in, responsible for their actions. If you bring a refuge in and he rapes someone, you should share his jail cell for he wouldn't be here to commit the crime if it were not for you letting him in. If you are responsible for bringing an immigrant in you are responsible for the harm they create. This should also apply financially. Rather than the state pay welfare for immigrants, it should be those who want them to come in.