Does this apply to Speaker Pelosi and other members of Congress--Republican or Democrat? Probably, but it doesn't make any difference. Bush has amply demonstrated that he has no intention of enforcing the law. Witness the Sandy Burger case, illegal immigrants, etc. The entire article is here.
The Logan Act makes it a felony and provides for a prison sentence of up to three years for any American, "without authority of the United States," to communicate with a foreign government in an effort to influence that government's behavior on any "disputes or controversies with the United States."