Previous posts have discussed the "revolving door" between government and the interest group community. The Center for Responsive Politics reports:
The revolving door goes two ways, and it works for staffers as well as for members of Congress. The more well-traveled direction is from government to corporation, trade group or other organization, often for more money than an individual can make working for Uncle Sam.
It's less common for people to go the other way, from the private sector to government, unless they've been elected to serve on Capitol Hill. But it does happen. In fact, according to an analysis by Remapping Debate and the Center for Responsive Politics, 41 high-ranking staffers for new members of Congress came from organizations that have a lobbying presence in Washington.
Hiring a staffer with experience in lobbying can be extremely helpful for a new lawmaker who needs to quickly build connections and might be concerned about securing funds for re-election. In many cases, legislators seemed to pick like-minded staffers, or at least ones with an extensive Rolodex who might be able to advance their pet causes.