The debate on Fast Track is less an argument about legislative strategy than it is an argument about free trade versus protectionism. There are three major objections to free trade and consequently Fast Track legislation. Free trade eliminates jobs. This argument has largely been debunked. While it is true that foreign trade will change the mix of jobs in a country, in aggregate, independent analysis show that free trade benefits both economies.
People often point to the trade deficit as evidence of failed trade legislation.
However, the trade deficit is a complex measure that may not be revealing the entire story. If one examines the data between 1970 to the present, the periods of slow or negative US economic growth are periods of small trade deficits. A robust US economy is correlated to higher trade deficits. We may open our markets, but other countries do not open theirs. This objection acknowledges the benefits of free trade, but wants to use trade negotiations as leverage to gain access to foreign markets.