There's two reasons to test drugs. (1) To know it's effective. (2) To know it's (reasonably) safe. Chloroquine has passed (2), which is relevant for this article.

Maybe Chloroquine hasn't been tested, but Hydroxychloroquine+azithomycin was tested in a tiny 36 person trial in France, and I believe that's what Trump is basing his "hunch" on. He heard and thought he understood some small snippet of information.

Prescription drug = a pharmaceutical drug that legally requires a medical prescription to be dispensed.

Personal responsibility = the idea that human beings choose, instigate, or otherwise cause their own actions.

Stupidity = behavior that shows a lack of good sense or judgment.

It's been confirmed effective against SARS CoV in vitro [1]. Before you say it, yes, I know treatments in vitro do not always work in vivo.

Reports from China, South Korea and France have suggested efficacy in humans against COVID-19.

1: https://www.ncbi.nlm.nih.gov/pubmed/15351731

Actually they rarely translate.

Chloroquine is a particularly funny example because they have already tried it as an antiviral drug several times without any efficacy.

Can you point to evidence that in vitro efficacy rarely translates to in vivo?

I've seen the one situation of chloroquine showing promise in vitro against SARS CoV but no others. Is there literature on others?