Anti-Corn-Law League

Obviously there are big differences between 19th century England and countries that today have high tariffs on agricultural products. But there is still one lesson to be learned from the British repeal of the Corn Laws in 1846: the role principles played in the face of practical considerations in securing the repeal (see quotes below). Note that the Corn Laws actually provided for tariffs on wheat(1).

Quoted from Landlordism and Liberty: Aristocratic Misrule and the Anti-Corn-Law League by Richard F. Spall, Jr.

The members of the Anti-Corn-Law League tended to view aristocratic privilege
and influence in political and social institutions as well as economic relationships
as forms of monopoly, and monopoly was something Leaguers opposed in all
its variations. This fact is central to an understanding of the nature and scope
of opposition to aristocratic misrule by the ACLL. Leaguers were part of an emerg-
ing liberal consensus that placed a very high value on freedom from the con-
straints of the state, particularly with respect to economic affairs; they opposed
the legacy of medieval restrictions and regulations on manufacuring and trade,
and deeply resented the continued influence of a privileged landed aristocracy.
This developing and cardinal liberal doctrine is in many ways summed up in
opposition to monopoly in all its manifestations, and the ACLL was no small
contributor to this tradition.

Quoted from "What Crushed the Corn Laws" by Eric Phillips

The repeal of the Corn Laws depended on shifting ideologies. Prime Minister Peel was persuaded to change his position on the issue through the power of argument alone, and he brought with him a large number from his party who were loyal to him. The landed classes had no direct economic interest in opening the country to free trade and they still possessed a stranglehold on political power. Cobden himself seriously doubted whether repeal would have carried in the face of continued opposition from Peel.[36]

Deterministic readings that ignore the events, people, and debates end up providing theory that is either myopic, insufficiently supported, or even contradictory to the facts. Lord Robbins is correct in his assessment: "Any account …of the coming of free trade in the United Kingdom which omitted the influence of economic thought and of economists would be defective and, indeed, absurd."[37]