...and I appreciate your effort to make the distinction between means and ends, economics and politics.
But, free trade is certainly to the advantage of *everyone* in the longer-term. Likewise with free markets in general. Various kinds of interventions, including tariffs or currency devaluations, can benefit certain groups for a time, but ultimately they impoverish everyone, including members of those groups. If the end is maximum prosperity for everyone, the means is free trade.
Re your point about the political implications of free trade, I think we need to disentangle free trade from the complex of statist policies now called "globalization." The two have *nothing* in common. Globalization is certainly a threat to liberty, free trade certainly is not.