What I object to is that in practice people just side with their politics "team" like in sports and create post-hoc justifications for policy created for unrelated reasons.
I'm in favor of evidence-based trade policy, but this isn't that unfortunately. The closest thing we have to evidence-based policy is the economic consensus, and the current administration is making a big show of disagreeing with the consensus for non-evidence-based reasons.
The current economic direction is not a consensus. The Western democracies are increasingly politically polarized and economically volatile.
Between the many different crises (unaffordable real estate, populational collapse, unsustainable environmental practices and global warming, increasing inequality, hollowing out of small and medium sized cities, and the list goes on), it is very difficult to justify the status quo.
You can estimate the impact objectively, but not whether that impact is good or bad.