You're making a very good point there.
One of the biggest subsidies for the US nuclear industry is the Price-Anderson Act, which makes the Feds provide insurance for otherwise-uninsurable nuke plants.
If the Price-Anderson Act was found unconstitutional/didnt pass/whatever, then you might have the lack of this truly massive public subsidy make the electric utilities think about backing a SPS, back in the heroic industry of the Space Age.
You still have the problem of 'put the solar cells on the ground', but this might see the US utilities get behind the project in the late sixties/early seventies.
You mean an act that charges $121 million a year per plant that covered $151 million , $70 million of which was over the Three Mile Island panic that killed not a single person ? https://en.wikipedia.org/wiki/Price–Anderson_Nuclear_Industries_Indemnity_Act According to the IAEA the average accumulated radiation dose of the "liquidators" who worked cleaning up Chernobyl was about 100 mSv which is less than the background radiation in naturally high radiation areas in India and China during the same period. The evacuees had about a third of that in "strict control zones" about 50 mSv and 20 in other contaminated areas and around 50 or so people have died so far as they can tell. https://www.iaea.org/technicalcooperation/documents/chernobyl.pdf Both in Chernobyl and Fukamishi more people probably died from the panic than the radiation.