Free trade has delivered unprecedented global prosperity. It has also caused trouble because there are always "winners and losers". If you don't take steps to blunt the effects of globalisation on the "losers" then you get dissatisfaction.
The first Twenty Five years of my life were lived in a totally protected economy with huge tariffs on imported goods and import quotas as well. It employed tens of thousands of bureaucrats to run the scheme, an imported lead pencil for example might attract an import duty of 12.5%, but the rate for a coloured pencil might be 5.0%, except if the pencil was black, when it was 12.5% because it could substitute for a lead pencil ...and then impoters would take cases about this to the High Court.
Locally produced cars cost over twice what they cost in America, and had half the features, performance and quality. I used to drool over "Road and Track". Women used to drool over the electrical appliances in American magazines. Even our clothes, locally made, were inferior, and if I was lucky, I got a new pair of Levis each year.
All protection does is allow management and unions to sit back and featherbed.