Free Trade with Columbia

Secretary of State Condolezza Rice has a column in today's Wall Street Journal regarding the free trade agreement with Columbia. I don't understand who could be against this agreement and why. In a world where we give favored nation status to Communist China - who could oppose treating a democracy in our own hemisphere to just as favorable terms? In an economy where everyone is warning about a coming bad spell - why would people want to repeat the mistakes of Smoot-Hawley on a lesser scale?

If there is a valid argument against the Free Trade Agreement with Columbia - I'd like to hear it.