They're referring to a decline in the strength of the US dollar. The value was "dragged" down

It may be a US company that exports to the rest of the world. Its revenues in weaker currencies abroad, when converted to USD, may be lower than they would be with a more favorable exchange rate. But their expenses (materials, staff salaries, etc.) may be largely in USD. So their earnings (income less expenses) are reduced by "a drag from the strength of the U.S.dollar".