Thanks for taking the hit from the "HN isn't about politics" crowd, this is something that needs to be said again and again.
Right wing conservatives and their followers - aka Republicans - are the number one threat facing the world today, hands down. Beyond their abhorrent legislative agenda based on their shared hatred for various parts of society, their complete disconnection from reality and traitorous attacks on democracy itself have essentially disqualified them as a legitimate political party.
In terms of lead's influence: My assumption has been simply that lead and mercury in the air caused a minor, yet statistically significant, impairment of cognitive ability which has robbed Boomers and much of GenX of their ability for both empathy and critical thinking. This has led to a swath of the population who is more susceptible to totalitarian messaging which always include intense hatred of others, conspiracies and wild accusations.
To paraphrase an old cliche: All Republicans are NOT lead-poisoned racist sociopaths that think Putin is a great leader, the virus is a hoax, the election was a fraud, etc. However, the reverse, is obviously quite accurate.