If economists think that the U.S.A. will benefit in the long run from "free" trade, why don't they advocate

Most economist do advocate free trade across the board, but resistance by industries and worker means that it only comes into the public debate piecemeal so the arguments favoring free trade by economist are on what ever is currently being debated. I do not recall any proposal that reduced restrictions on trade that did not have the support of the vast majority of economist.