Ah, free trade. Pretty much all economists agree that the economic pie will get larger, but they are silent about how the pie will be split. Therein lies the problem.

Most economists will trumpet the increase in societal or collective well-being but will not give you a straight answer about who accrues the gains, who accrues the losses, and what amends -- if any -- should be made towards the economic losers to encourage them to support the proposed schemes. When asked about these matters, most economists claim that these are outside their science. They are then surprised that their science is less than relevant and that people refuse to go along with their plans.

EDIT: If you disagree with my assessment please explain your reasons instead of downvoting.

EDIT: Added the second paragraph for clarification.