I linked to some of those very facts earlier. There's no reason not to start there, rather than working backwards from what MSNBC is doing. (And no, that stuff was not just for "talking about" the possibility; he recklessly said "what have you got to lose?" about a drug that can kill you if not taken in the right dosage.)
The fact that they're so zealous about this doesn't tell us anything, since that's what you'd expect both if they were being partisan and if they were right. They also might be, ya' know, both.
As always, Trump's public speaking abilities are sometimes questionable to say the least (one of his many faults), but the spirit of what he's talking about is usually discernible.
At the time he said "
what have you got to lose" projections for the virus were horrifying & people were dying from it rapidly.
So his saying "what have you got to lose" was quite obviously not advice to the average joe to go buy some at the drug store and take it because it would be fun (like "try it, you'll like it"), but rather intended for people who were headed for death (when your prognosis is death, you have nothing else to lose).
The biggest caveat for this somewhat misplaced saying was that the drug can only be obtained via a doctor's prescription (and Trump knew this).
No one can just go buy some over-the-counter to "try" it. So the obvious inference was, if your prognosis from a doctor is a dire one, then trying anything that your doctor could prescribe (in this case a drug that's been approved for a variety of diseases for over half a century and had already shown some success for Covid19 sufferers) is better than doing nothing or trying to ride it out, hoping for the best as symptoms are becoming more fatal by the hour.
Also, to be taken into account (and this goes for everyone, not just Trump, on either side of the aisle including Drs. Fauci and Birx) that many statements made throughout this crisis have been based only on what's known at the time - when Trump started talking about Hydroxy-C it was not yet known that it proved ineffective on patients in advanced stages of the virus. All that was known at that time was that many doctors had had some success using it on patients in earlier stages.