Am I the only one that have the feeling of seeing the ridiculous argument more and more often: "We should not dismiss scientific research just because the findings don't align with YOUR politics and accuse the scientist to be obviously politically motivated. This researcher that produced findings that align with MY politics has been criticized by scientists whose finding don't align with MY politics, so I'm not hesitating of accusing these scientists to be obviously politically motivated".

Yes, I'm sure such easy accusations exist. Not long ago, climate change was "left-wing", and now that we know that it's just science, people should remember who often scientists that were just doing their job were dismissed for being left-wing.

But on the other hand, on the left and the right, scientists are human and are biased by their understanding of how the world works and should work.

For Haidt, I don't have a specific opinion yet, but there are few elements that make me think that, even if he is not conscious about it himself, he may be politically biased:

1) In a lot of his writing, I never really see him taking bias-control measure seriously. He seems, at the end, despite what he may say sometimes, to consider himself "too smart to be biased", which is not a good thing. Having bias-control measures (aka starting from the hypothesis that maybe my conclusions are biased) is an easy and harmless way to do good science (even CERN is doing it by asking members of the Atlas and CMS collaboration to not exchange on non-published results).

2) The scientific critics are pointing at scientific elements that are legitimate. They are not saying "I don't like these findings, so I will say Haidt is right-wing", they are saying "there is a scientific problem with these findings". The large majority of them don't even say that Haidt is politically motivated. The "politically motivated" is appearing after, when people try to understand why Haidt will prefer some conclusions over others while they both are as scientifically grounded.
In particular, I'm far from convinced by his counter-argument. For example, "the map for the territory" argument seems to say "stats is hard, so it's ok to claim we are sure even if stats say we are statistically not sure", or "the pascal's wager" argument seems very political "dropping some left-wing values and reinforcing some right-wing values is just all benefits, because obviously we are better off in a right-wing value society"

3) Scientists that are "neutral" will sometimes find findings that are politically neutral (for example: "I find that butter has an impact on mental health"), sometimes left-wing (for example: "I find that some traditional values have a negative impact on mental health"), sometimes right-wing. But if a neutral scientist is studying different topic and, by chance, always ends up with the findings that corresponds to what a right-wing person would think, this is suspicious. Haidt have worked on different topics, as you say for 11 years, and apparently, his reputation for preferring a conclusion more aligned with moderate right-wing is not due to his last topic, but from the observation that a truly neutral scientist will sometimes align with right-wing, but sometimes with left-wing too.