First, in principle it could contribute to compressing firms’ price-cost markups as competitive forces resulting from trade openness would depress profit mark-ups of domestic firms competing with international firms. In practice, however, such effects have been hard to identify and, indeed, aggregate profitability has remained high.
I do believe, though, that there are good reasons for a more level-headed assessment – especially when looking through the cycles as perceived by the public and reported on in the news and seeing some years into the future.