A recent article in the New York Times reports:
Dozens of written reports detailing summaries of official visits by members of Congress to foreign nations that were included in the vast trove of State Department documents obtained by the WikiLeaks group and reviewed by The New York Times … show that Congressional trips are often much more than simply fact-finding missions.
Lawmakers also use their access to top foreign leaders to advocate for homegrown economic interests.
Senator Maria Cantwell, Democrat of Washington, pressed top government officials in China last year to allow SSA Marine — a Seattle-based maritime company — to open a port terminal in China, a State Department cable shows.
See the full New York Times article here
[...] I found that tidbit via Longshore & Shipping News. [...]