One of the most bizarre incidents in Presidential history probably launched the so-called war on drugs. In December 1970, Elvis Presley, who was clad in a purple velvet suit, unexpectedly dropped in on President Richard Nixon at the White House. After presenting the somewhat befuddled Nixon with a Colt .45 pistol, Elvis insisted that he was an authority on "drug abuse and Communist brainwashing techniques," so he would be an excellent undercover marshal. Nixon politely refused the singer's assistance. Even now, the Elvis-Nixon photo remains iconic.
In the colonial period, British officials often used blank search warrants to enter private property with little or no cause. To end this practice, the Founding Fathers included the Fourth Amendment in the Bill of Rights. Later, courts used the Fourteenth Amendment to apply this provision to state law enforcement agencies.
In the seemingly endless "war against drugs," the number of successful prosecutions is basically the only yardstick of success. So, Texas prosecutors are very aggressive in these cases, at both the state and federal level.