If POTUS had challenged the danger of the/a virus… They would have attacked him for not being a virologist.

If POTUS challenged the origin, more than he did… They would have gone further with xenophobia.

If he had pushed tonic and zinc any more… again with not being a Doctor.

Death Certificates, Medical Records, Testing, even the economics… his word against Theirs. And Theirs was at that time much more powerful than it is today, only weeks later.