US Border control policy has become one of the administration turning illegal aliens back in much the way as a drover pushes cattle in one direction or another to avoid making arrests. In this way, they can demonstrate success. One other possible solution would be to make the border harder to cross, but then all of those potential Democratic voters who make it north --- wouldn't make it.
And then what would happen to the Mexican drug cartels who work so hard to get their product into American veins? Some people claim that, "they'll just find another way." While that may be true for a small percentage of the narcotics that come north, the vast majority would be stopped by a hard border.
The Obama Administration has not yet been able to form a coherent border control strategy to reduce the flow of illegal aliens and "take back" the portions of the US Border that are currently under the nearly complete control of organized crime.
A number of solutions have been posited and many of them have been set forth here on Virtual Mirage, but the US seems to be able to only focus on one thing at a time. The US-Mexico Border grabs the spotlight when a family is slaughtered by narcotics cartels, but now that we are in 'campaign mode', the Border issue will be put off again until somebody other than Obama becomes chief executive.