Is Democratic trade anxiety too late?

Dean Baker deviates from the Democratic base‘s obsession with halting new trade agreements:

As a practical matter, the country has already gone about as far as it can in placing its manufacturing workers in competition with low-wage workers in the developing world. The impact of any future trade deals on the US economy will be almost imperceptible.

The latter sentence may be true with regard to low-wage workers; it’s not true generally, unless Baker is implying that “any future trade deals” will be limited by political constraints. We can certainly imagine trade deals that would have noticeable impacts.