Thea Lee on NAFTA Chapter 11

I've been intrigued with the brief mentions of investor-state arbitration during the Presidential campaign.  Here is something on this subject from Thea Lee, policy director for the American Federation of Labor and Congress of Industrial Organizations (AFL-CIO):

The NAFTA investment chapter should also be revisited. NAFTA was the first trade agreement that allowed corporations to sue governments and challenge statutes protecting the environment, public health, and consumers. Legislators and ordinary citizens have no effective voice in the dispute resolution process. We would argue for eliminating the investor-state dispute settlement provision and more carefully defining both “investment” and “expropriation.”

I wonder if this could become important in the general election.  McCain seems to support trade agreements as currently written, but the Democrats have been quite critical.  So which candidate, Clinton or Obama, is more likely to follow the AFL-CIO view?  Based on this AP article, it could be either, although Clinton may be (slightly) more closely tied to the AFL-CIO:

The AFL-CIO has not endorsed either Clinton or Obama in the Democratic presidential primary, although it has allowed its 56 member unions to make individual endorsements. Clinton so far has been endorsed by more AFL-CIO unions than Obama.

Clinton has made explicit criticisms of investor-state dispute provisions (see the first link above); I haven't seen anything from Obama, though.