The Wall Between Contractors and Politics Since 1940, it has been illegal for federal government contractors to contribute to federal political campaigns or parties. But in the new unregulated, unlimited jungle of campaign finance, Mitt Romney's super PAC is allowing some contractors to violate that historic ban, taking yet another dangerous step toward a culture where government business is done on a pay-to-play basis. The ban on contractor donations is a broad one, applying to "any political party, committee, or candidate for public office, or to any person for any political purpose or use." It goes back seven decades to the Hatch Act, and was designed to eliminate two practices that had led to corruption in Washington: companies using political donations to bribe their way to a lucrative federal contract, and lawmakers extorting money from companies that wished to do business with the government. That law has remained on the books in various forms - though, unfortunately, it was watered down a bit in the 1970s to allow contractors to set up political-action committees that accept money from their employees and then donate it to candidates. But the ban on contractors using their own money to contribute was unchanged. The Citizens United decision allowed corporations and unions to contribute unlimited amounts to so-called independent political groups, but it did not address the contractor ban. Given the long history of that ban, most third-party groups wisely assumed that it remained in place. For example, American Crossroads, the conservative super PAC formed by Karl Rove, requires donors to certify that the money does not come "from the treasury of an entity or person who is a federal contractor." The same requirement is made by the super PACs supporting President Obama, Rick Santorum, Newt Gingrich and Ron Paul. But not Mr. Romney's super PAC, Restore Our Future, which does not impose that condition. The Los Angeles Times recently reported that the group has accepted donations from at least five government contractors, totaling $890,000. The biggest was from Oxbow Carbon, founded by the billionaire William Koch, which has a contract to sell coal to the Tennessee Valley Authority. One engineering contractor asked for a refund after being contacted by the newspaper, but not the others. Restore Our Future officials would not discuss their thinking, but if they believe that Citizens United gives them immunity from the contractor ban, they are on shaky legal ground. The Federal Election Commission decision that gave birth to the first super PAC did so explicitly with the understanding that the group would not take contractor money. And in a current lawsuit brought by a group of small contractors who want to contribute to political campaigns, the F.E.C. has made it clear that it believes the ban remains in effect "to serve important government interests in deterring corruption." Lifting the ban during a campaign, F.E.C. lawyers wrote, could damage public confidence in the campaign-finance and contracting systems. Mr. Romney improbably claims his campaign has nothing to do with his super PAC, but if it acquires a reputation for skirting the law, it will rub off on him, too. He should make clear that he wants the group to return all contractor contributions, and accept no more of them.