If it was only a question of drug routes, that could be resolved overnight without a fence if the will were there on both sides of the border. But to maintain open borders for the new slave class, the powers that be will downplay the drug routes and amuse the people with the Mexican Hat Dance on the Senate floor, leaving the border problem on the back burner.
In addition, if the PTB make more money on the drug trade than they do on the alien worker program, the 'doing the jobs that Americans won't do' ploy covers what's happening behind the curtain or under the table where the real action is. In which case, the border never be secured -- fence or not.
IMO.
correction : border never = border will never