Nah, that is not really true. There has been a significant bump due to covid, but before covid the test results have shown constant improvements.

That said, I don’t think IQ and political idiocy are that strongly correlated. I’ve met a lot of highly trained people, who would doubtlessly get great IQ test results, who are politically extremely gullible.

That also said, IQ tests are also a quite flawed way to assess intelligence.