None of these are great threats. In all three cases the mishandeling of the issue has done more harm than the issue itself. Not that they are not dangerous, but the degree to which they are used as political scapegoating is significant. Of the three drugs is the most dangerous, but in saying this I mean prescription drugs.

Great threats to the US include climate change, Russian aggression, and income inequality. There are others but you get the idea.

Opiate drugs. We should watch terrorism and illegal immigrants. Anyone that suddenly believed illegal immigrants became a problem after the last presidential election is a moron.

D. Guns.

Trump

your inward gazing the lack of funds for basic education the way you treat most of your citizens terrorism drugs and immigrants are way down the list of things that are negatively impacting your country

Interesting question:

You should have posted it as a survey so it could generate a graph.

Given you selection:

In this order: Drugs, terrorism, but immigrants? I'm not sure I would even place immigrants on a "great threat" category as any immigrant that would be a threat are already covered in "terrorism" category.

There are many other greater threats you did not mention. Given a larger list. Drugs would be far down the "dangers" list. . .

Trumpus assholis maximus.

the brainwashing of the american public to the extent that they are unable to tell what is factual and what is fictional. that is a kind of terrorism.

g

White supremacists and Nazi supporters.

America is a nation of immigrants.

Terrorism

We are a nation of immigrants (contrary to what the current administration thinks)

The opiod crisis is doing terrible things but seems to be slowly coming under control... Or at least getting slightly better! (Thanks to the hard work of Jared Kushner!)

Let's face it... If you are stoned, you aren't a danger to anyone except a Twinkie!