ThinkProgress has the story:
...the Chamber funds its political attack campaign out of its general
account, which solicits foreign funding. ... According to legal experts consulted by ThinkProgress, the Chamber is likely skirting longstanding campaign finance law that bans the involvement of foreign corporations in American elections.
The Chamber is funding attack ads against candidates the Teamsters strongly support: Jerry Brown for governor of California, Barbara Boxer for senator from California, Jack Conway for Senator from Kentucky.
...the U.S. Chamber of Commerce raises well over $100,000 a year in money from foreign businesses through its operation in Bahrain...
It also has an office in India, where it boasts it can help U.S. companies outsource jobs and collects $200,000 a year. And it has an affiliate in Egypt. And it has a secret relationship with an affiliate in Russia, but we can guess what that's all about.
Here's why the Chamber is able to gather so much money from foreign companies (and, we suspect, foreign government-owned companies):
The Chamber has repeatedly sent out issue alerts attacking Democratic efforts to encourage businesses to hire locally rather than outsource to foreign counties. The Chamber has also bitterly fought Democrats for opposing unfettered free trade deals.
A reminder to the Chamber: it's against the law for foreign entities to contribute to political races here in America.