An expert's take on the Colombia/NAFTA issue

One of my current government teachers (who I'll let remain anonymous for now, because I didn't ask his permission to publish his words in this blog) specializes in Latin American politics, so I thought I'd shoot him an e-mail regarding the stalled trade agreement with Colombia. Here's what I asked:

I'm a student currently in your GOV 312 class, and knowing that your specialty
is Latin America was wondering if you had any perspective on the partisan
nature of a potential free trade agreement with Colombia. I've read plenty of
arguments from the right in support of an agreement, but am struggling to get a
perspective on the Democratic opposition to this issue. Being a person who
trusts our legislators in good faith (a naive position, perhaps), I am hesitant
to apply the Ginsberg/Schefter hypothesis to this, that their tight connection
with unions is preventing anything from being accomplished. However, the fact
that the bill is now about to be tabled due to a rule change is leading me more
and more to the conclusion that this bill would probably benefit both nations
and pass if put up for a vote.

It being an election year, and the need to appeal to union-oriented swing states
of Michigan, Ohio, Pennsylvania, etc. seems to be the only reason for opposition
from the Democrats. The lewd waffling of Obama and Clinton on the NAFTA issue
further leads me to this conclusion. If you could offer any perspective on the
Democrats position, even if you support an agreement and have to play devil's
advocate, I would appreciate it.

To give a little background, we had to read the book Politics By Other Means by Ginsberg and Shefter, who's thesis is essentially that politicians don't really care about the issues, but only retaining power entrenched in their institutions. A classic example for the right would be the military, while the Environmental Protection Agency is one for the left. A dismal hypothesis, which I tend to disagree with on most issues, but in some it seems evident. Anyway, here is my professor's response:

I am afraid I must agree with the cynical Ginsberg & Shefter interpretation on this issue! US Trade with Colombia is very limited, around 18 Bio $/Year, I believe, ie the issue is primarily symbolic. But it has been caught up in this primary campaign, in the way you state -- and you mention the irresponsible insinuations about NAFTA, which can't really have been sincere [but they did get the Mexicans & Canadians worried]. In general, so much of US trade policy is driven by fairly narrow interest groups, not only unions but also protectionist sectors of business. It's a shame in this case because from the perspective of broader US interests, it's important to "reward" a staunch ally like Colombia's Pres. Uribe, especially because Uribe faces so much "heat" from leftist leaders such as Hugo Chavez. If the US cannot consistently support its friends, its adversaries will be happy! This whole process really doesn't look very good, from the perspective of broader US interests!

It's good to know someone with much more insight and knowledge than me also sees through the politicking of Obama and Clinton on this issue. Again, I feel vindicated.

UPDATE: Sorry about the horrid formatting of my portion of the dialog, but that's the way it pasted and I can't figure out how to make it more readable.