An N95 mask made in China costs $0.30. One made in the USA costs $1.00. A 25% tariff was enacted by executive fiat. The made in China mask is still cheaper than the USA made one. Few hospitals buy American. PPE manufacturers in Malaysia win.
It's very basic though. Americans have to follow laws, including regulations from EPA, OSHA, building codes, routine inspections (e.g. health inspections), and taxes and permits.
External companies don't face as many of these hurdles. Mexico doesn't have to report to the EPA or OSHA, so if implementing better work environments or cleaner air is important, tariffs act as a tax to instead manufacture in America and, in effect, follow those regulations.
You'd have to somehow convince or force hospitals to pay more for disposable medical supplies. They're not going to pick the USA made mask when they can get a Malaysian one. Domestic manufacturers are only going to build new plants and hire with a long term policy shift.
Americans would be pissed once everything triples in price.
If we only tariffed China, yes. They would be. Because while their 37.5¢ mask remains 63% cheaper than the American one, it might be 20% more expensive than one made in Mexico or India or Vietnam. But we didn't do that. We raised the prices for everyone. So those orders are, more likely than not, still going to go to China. There will just be some middle men taking a cut along the way.