Many Americans grumble that the U.S. Congress lacks the courage to exert its constitutional role by challenging abuses of the Bush administration. They may be interested in knowing how Congressmen are selected before they are elected. Even before party primaries begin, powerful groups select their favorites and back them with money and media support. One of the most powerful groups in the USA is the "intelligence community" that operates from secret budgets estimated at $44 billion a year. One must assume that they might use their influence and money to insert spooks into Congress to serve their needs.
This has already happened, as this debate in the halls of Congress revealed:
http://www.sandersresearch.com/index.php?option=com_content&task=view&id=939&Itemid=67