Practice or Process?

Attorney General Eric Holder announced that US attorneys had be instructed to sidestep the mandatory minimum sentencing rules in regard to "low level drug offenders".  Not a bad idea,  Users and guys who deal just enough to support their own habits aren't that dangerous.  But I don't like the process Holder used. 
   Those mandatory minimum laws were passed by Congress.  The right way to change 'em  is to go to Congress and get Congress to change the law.  Doing it on just Eric's say-so ain't democratic, that's what dictators do.