Tearing apart families and kicking people out of our country is not necessary. Reform immigration so there is a clear, straight-forward path to citizenship. Then people will stop trying to come in the back door and immigrant families currently living in the us will happily start taking steps to aquire citizenship. 
Also, please keep in mind that, although undocumented immigrants cost us money, they also help us. In fact our economy is largely dependent on them. Don't just listen to biased sources that only mention the negative part. The net sum of both halves of the equation is not a clear positive or negative. We should probably make sure there is a clear benefit to deportation before sending all that money to tear families apart and ruin lives.