Northrop Grumman, which builds the airborne radar systems that the Senate bill orders up (a total of six at $9.3 million each), has given more money to federal candidates than any other defense contractor and is No. 9 on the Center for Responsive Politics' list of all-time biggest lobbying tabs. As of the end of last year, Northrop Grumman had spent more than $191 million trying to influence Congress and the company's political action committee and employees had made a whopping $17 million in campaign contributions, the company's Influence Explorer profile shows. During the 2012 campaign cycle, Northrop Grumman and its employees gave about $500,000 to Senate candidates, and more than $46,000 each to the Democratic Senatorial Campaign Committee and the National Republican Senatorial Committee.