A welfare state can not have a free trade policy. The welfare system diminishes any benefit the citizens of the state would receive from free trade by redirecting the costs of free trade to the taxpayers.
What you gain on cheaper goods you lose on higher taxes to pay for the costs and disruptions due to free trade. The welfare system also allows unbalanced trade to occur.
In the real world if trade caused a person to lose his job, he would not be able to buy the imported good until he found or created another job. This is the free market supply and demand. In a welfare state the welfare would still allow the purchase of the cheap goods.
The costs of that purchase is paid for by the taxpayer instead of the consumer. The taxes goes to the producer/country and one natural correction of unbalanced trade is removed. The trade can continue with no natural brakes on the trade until the welfare state is bankrupt
Most people understand you can't have an open border and free flow of poor immigrants into a welfare state. The system would be quickly bankrupt as the costs to feed, house and care for those immigrants over takes the ability of the state to pay.
The same is true when it comes to an "open border" on trade.
