You're touching on what is probably the real reason. Volvo has an extensive dealer network in the US, and dealers are traditionally involved in the political process (i.e. they lobby extensively). Also Volvos enjoy a decent market share and brand recognition. Polestar on the other hand only sold in single digit thousands in the past couple of years and are definitely not as well known. There's not a lot of difference otherwise, Polestar 3 is 95% identical to Volvo EX90 and they're both manufactured at Volvo's South Carolina plant mainly from Chinese parts. Polestar 4 is indeed diferent, based on Zeeker 001 and manufactured in South Korea. Anyways, my guess is Polestar didn't jump through the hoops and didn't grease the right wheels, probably because it was not worth the trouble for what is about 5-6% of their global market share