That includes the federal contractor ban, which was originally passed by Congress in 1940 and made it illegal for individuals and companies with government contracts to make federal contributions. It also barred solicitation of such contributions. An FEC regulation passed in 1976 expanded the law to ban federal contractors from making expenditures in support of candidates for federal office.
"What we have is many FEC regulations that are on the books today but are clearly unconstitutional," Kelner said. "So in that environment, it is not surprising to me that some companies will decide to forge ahead.... What's the enforcement risk?"
An FEC spokeswoman declined to comment. But the commission is defending the ban in a case filed in federal court in Washington in October by several contractors, indicating that the agency still views the law as constitutional. And at a House oversight hearing last year, a Democratic member of the commission, Cynthia L. Bauerly, testified that the prohibition still holds.
Federal contracting records and campaign finance data provided by the Sunlight Foundation, a nonpartisan group that promotes transparency in government, show that three other companies with federal contracts made contributions to Restore Our Future:
• B/E Aerospace, a publicly traded corporation in Florida that gave the super PAC $50,000 in June 2011, provides rivets and other components to the Department of Defense and other parts of the government. It has won more than $8.2 million in federal contracts since January 2011. Its chief executive and chief financial officer each gave Romney's campaign $2,500, the maximum allowed in the primary.
• Florida- and Puerto Rico-based Clinical Medical Services, which provides medical supplies to the Department of Veterans Affairs, donated $25,000 on Jan. 4. It has won government contracts worth almost $4.3 million since the start of last year.
• Boston-based Suffolk Construction Co., which holds a $20-million building contract for a Rhode Island naval base, made three donations to the super PAC totaling $60,000. The firm is headed by Obama bundler John Fish, who has given to Democrats and Republicans.
The three companies did not respond to requests for comment.
Times staff writer Maloy Moore in Los Angeles contributed to this report.