Yes, Portlanders are very proud of their water supply and want to keep it pure and "natural", despite any science that indicates the value of fluoride. Despite the science strongly in favor of some GMO products, such as golden rice, or vaccinations, there are some who hold onto their beliefs. Extrapolating from that to some overall condemnation and ridicule is illogical.
The guilt by association notion is ridiculous here, but it's become a staple of politics. Whether or not he's a birther is largely irrelevant to his actions. Whether or not he's "far right wing" is pretty irrelevant as well. The only relevancy is attempting to do a political "7 steps to Kevin Bacon" as a means of attempting to smear "The right" and those within it as a whole based on the individual actions of one man.
The reality is crazy conspiracy theorists reside on all sides of the political spectrum and, by and large, rarely actually represent an accurate depiction of the vast majority of those within that political wing.
"I am appalled that somebody who is the nominee...would take that kind of position"
"A court took away a presidency"
"...the brother of a man running for president was the governor of the state..."
It's horrifying because Trump is blunt instead of making overt implications.
When some 'libbo' goes off the reservation that is just a typical libbo, and ALL libbos are like this and must be eliminated.
When some CON nut job goes off the reservation well that's just ONE bad apple (Speeches about DNA purity, racist signs, shooting cops, and calls for politicians who don't vote the way the CON loud mouth wants to be frogmarched out and shot, or some punk 'macho' speak about long range assassination)
Radical mindsets breed radical actions- unfortunately most of the big talkers are too cowardly to back their crap up but it does incite others.