Yep you're right, that would be another possible legitimate (sort of) use of tariffs. Make the case that (for example) steel production is a vital national interest which must be defended even if it results in higher steel prices.

Of course it will result in higher prices, that's the point, but also the part politicians aren't too keen to spell out

You misunderstand. Tariffs have always been in place like this. They are just expanded now. Enacted in 1988 via the Omnibus Trade and Competitiveness Act, the HTS replaced the older Tariff Schedules of the United States and took effect January 1, 1989. It aligns with the World Customs Organization's HS, adopted globally by over 200 countries. https://hts.usitc.gov/

You can see the archive going to "2015 and older" here https://hts.usitc.gov/download/archive

Do you think I’m under the belief tariffs are actually new?

Sorry buddy but it is you who misunderstands.