Less than four weeks after winning re-election to a ninth term in Congress with more than 70 percent of the vote, Rep. Jo Ann Emerson announced Monday that she'll be leaving in February to head the National Rural Electric Cooperative Association. Emerging from a Depression-era effort to bring electricity to farm communities, the non-profit association has grown into a heavy Washington hitter: It's Influence Explorer profile shows more than $27 million in campaign contributions and $46 million in expenditures to lobby Congress, mainly on energy and tax issues.

In a statement, Emerson said she will "miss the constituents I work with every day." But she may have a consolation prize: Glenn English, the retiring CEO of the cooperative association and another former member of Congress, made more than $1.5 million in 2010, according to the organization's tax forms, which Sunlight viewed through Guidestar. The current annual salary for members of Congress is $174,000.

Data downloaded from Influence Explorer shows that over the last two decades, the Rural Electric Cooperative Association has contributed more than $72,000 to Emerson and her husband, the late Rep. Bill Emerson, whom she succeeded in office. The Cooperative Association also has donated $20,000 to GO JO, Emerson's leadership PAC.

House rules prohibit Emerson from directly lobbying her former colleagues for one year but nothing prevents her from using her personal contacts to open doors for colleagues who do.

Emerson's departure means that Missouri Gov. Jay Nixon will have to call a special election to fill her seat. Sarah Steelman, a tea party favorite who ran unsuccessfully for her party's Senate nomination this year, is one name being mentioned. 

(Updated 3/20/14: This post has been updated to correct the span of time that members of the House must wait before they are legal to lobby their former colleagues.)