Your first link says 28% support it, so somewhere between 28 and 37%. I do wonder how many of those people could find Iran on a map, though I suppose you could ask the same about the people who are against it.

The first link (YouGov) in fact is even less enthusiastic than GP quoted: 28% of Americans strongly or somewhat support the war with Iran.

(setting aside that it's illegal under international law, and unauthorized by Congress)

I lost trust in humanity when I saw how many people on HN fell for the CERN Mario Kart April fools article.