Yes they can stop it. We need to get more people to vote for legalization.
At first I thought that, but as this farce of an administration (or government reality tv, choose your insult I suppose) has dragged its feet to the grave like the grumpy old men that they are the more I've realize that at best they can have a chilling effect.
1. The DOJ has said Jeff Sessions can't do much of what he wants to do, in part because of his conflicting statements both before and after his appointment but also the lack of manpower and resources to fully reimplement that drug war, which soulful face open hostility at the public and state levels.
2. The pot Industry has grown, well like a weed, in many state economies as well as has already caused migratory shifts (people are moving to these states), which bolsters those states power in the senate that has legalized as well at the same time weakening the states that haven't.
3. If the "President" were to sign an executive order it would be seen as the federal government over reaching its authority in what is rapidly been turned into a states rights issue, something the republicans love to pull out on many issues. If the republicans allowed "The president" to make such an order it would be seen as a betrayal of One of their core values to the American people. Considering the midterm elections will see many political players up for re-election i'm both sides of the aisle, the republicans are fully aware they are already facing devastating losses in 15 months, a draconian move like this would see them lose a lot more, not only removing their stranglehold on the federal government, but likely seen them lose their majority in possibly even becoming something of a distinct minority party (I am not necessarily saying that cannabis is that huge of an issue, but the principle of the act would have devastating consequences for a party devastated on many fronts).
4. Let's say for a second that the above 3 points were thrown out the window and that despite the insanity "The president" signed an executive order reinstating the drug war, the amount of literature, skill and most importantly of all, seeds, in the country right now would see it go back underground but at 10 times it's strength that the task of "deweeding" the nation would be impossible to even try to enforce like it was at the peak of the drug war. What's more the sudden loss of tax money in the states would hurt the economy of those states an in turn it would be blamed once again on the republicans.
In short, I don't see any sort of significance of packs occurring in the next 15 months from the federal level, more likely it's going to be at the state level, so once again vote, be informed and inform and avoid the negative stereotype. Come mid term election, consider stepping it up a bit, we'll be able to "make America sane again".