The difference is between using and abusing power.
George W. Bush is exercising his legitimate constitutional powers to surveil suspected foreign agents for national security purposes, without benefit of a warrant.
Hpwever, Hillary Clinton would be abusing her constitutional authority if she was surveiling you without a warrant because you were suspected of growing marijuana.
Recall that the Clintons were able to conduct all sorts of nefarious beyond-the-law actions during their reign simply because they ignored existing laws, not because they were enabled by them.
Out best defense against a Hillary Clinton is the ballot box, not legislation that restricts the executive.
The government has already officially tied drugs to international terrorism, so that isn't a stretch at all. Hillary just needs to slap a "terrorism" label on any situation where she wants to circumvent the Constitution.