At issue is the constitutionality of banning corporate expenditures to influence federal elections. That ban, enacted in 1947, has been a cornerstone of ensuring fair elections.

A decision from the court that could overturn the prohibition is expected soon. Many observers fear that a majority of justices, led by Chief Justice John Roberts Jr., are inclined to do just that.

Current law allows corporations and labor unions to set up political action committees to collect donations and spend them on political activities. But corporations and unions are not allowed to spend money from their treasuries on federal elections.

The reasons for this restriction are as sound as they were a half-century ago. It's an attempt to keep a level playing field and to ensure that the concerns of average citizens don't get drowned out.

Total spending on federal elections in 2008 was more than $3 billion from political parties, outside groups, candidates, and PACs. While that's a lot of money, imagine how much disproportional influence could be wielded by a Goldman Sachs, or a Microsoft, pouring money from its corporate treasury directly into individual races for the U.S. House or Senate. During the 2008 election cycle, Fortune 100 companies amassed profits of $605 billion.

Corporations already outspend unions by a 4-1 ratio in PAC donations in federal elections, and they spend 60 times more than organized labor on lobbying.

The debate over health-care reform is a good indication of how vastly corporations could ramp up their campaign spending, if allowed. The health-care and insurance industries alone spent $1.6 billion lobbying Congress in the 2008 election cycle. As the government watchdog group Common Cause noted, it's nearly double the spending by all 470 winning congressional candidates in 2008.

And one trade association, the Pharmaceutical Research and Manufacturers of America, initiated a $150 million campaign to support a Senate bill without a public insurance option.

Rescinding these sensible limits on campaign donations would escalate a campaign fund-raising race that already consumes too much of candidates' time. But if the Supreme Court unwisely decides to erase established law, there is another potential solution awaiting in Congress.

The Fair Elections Now Act would create a voluntary system of campaign finance in which candidates could accept a mix of small donations of up to $100, and matching public funds. Similar systems have worked well in state elections in Maine, Arizona, and Connecticut. New Jersey experimented with a pilot program in 2007.

A House bill has 114 cosponsors, and was the subject of a July hearing in the House Administration Committee chaired by Rep. Bob Brady (D., Pa.) The committee hasn't voted on it, but if the court decides to undermine election fairness, Brady should advance this bill. The alternative is an undemocratic arms race that would trample the voices of ordinary citizens.