I can get to more technical papers, but it's not a big secret what you have quoted. E.g. The Economist quotes MIT professor John Van Reenen:
But just because the size of the pie expands [due to free trade], it doesn’t mean that everyone is better off. There are going to be some losers whose slice of the pie is so much smaller that they would have been better off with less trade. However, because the overall size of the pie has got bigger, the government can compensate the losers which can still make everyone better off. [...] But remember: thanks to free trade, you can afford that [better welfare programs], because the overall size of the pie is bigger.
And Harvard prof. Dani Rodrik writes:
there is one Stolper–Samuelson-like result that is
extremely general, and which can be stated as
follows. Under competitive conditions, as long as
the importable good(s) continue to be produced at
home – that is, ruling out complete specialization –
there is always at least one factor of production that
is rendered worse off by the liberalization of trade.
In other words, trade generically produces losers.
The proof of this result is simple enough to be
stated quickly here. [the proof is still like half a page]
More recent work in trade theory has emphasized
heterogeneity among firms and workers. These
models have additional margins for redistribution,
between firms and workers that otherwise look
quite similar. Grossman, Helpman, & Kircher (2017), for example, enrich the Stolper–Samuelson
framework by considering heterogeneity within
broad worker categories. ‘‘Managers’’ and ‘‘workers’’
must combine in teams, and their productivity
depends on the quality of the match. Trade liberalization induces re-matching and generates distributional effects within occupations and industries,
in addition to the standard effects across broad
factors of production and industries.
Hence in all these models, redistribution is the
flip side of the gains from trade. No pain, no gain.
My point is not to say that these theoretical models 100% apply to the complex realities of international trade, but rather that economists are aware that under certain conditions some segment of the workforce can be worse-off with free trade... unless something else happens.
Nevertheless, the prevailing opinion among economists, or at least US academic economists surveyed by IGM is that the long term benefits of free trade outweigh the short-term negatives (including [un]employment in some sectors).
As the survey additionally collected fill-in comments/responses, they are an interesting reading, but the first one (alphabetically, from Acemoglu) probably summarizes the critique you inquire about:
Economists often understate short-term employment costs, which are significant and unequally distributed, but probably less than benefits.
As an example of empirical work evaluating such effects in a concrete context, Caliendo et al. (2015)
find that China's import competition growth resulted in 0.6 percentage point reduction in the share
of manufacturing employment, approximately 1 million jobs lost, or about 60% of the change in the
manufacturing employment share not explained by a secular trend. Overall, China's shock increases
U.S. welfare by 6.7% in the long-run and by 0.2% in the short-run with very heterogeneous effects
across labor markets.
Related enough, a more recent IGM survey of a panel of European economists (some of which do work in the US though) shows that they are not blind to the effects of inequality on [liberal] democracy. The latter survey also poses questions on whether higher government spending is justified from this perspective. So compensating or at least caring for losers (not necessarily stemming from free trade alone) is also a topic that economists are not opposed to. (Whether they should talk more about it, is a different issue.)