This past election, the American people sent a clear message to Washington: Clean up your act.

After a year in which too many scandals revealed the influence special interests wield over Washington, it's no surprise that so many incumbents were defeated and that polls said "corruption" was the grievance cited most frequently by the voters.

It would be a mistake, however, to conclude that this message was intended for only one party or politician. The votes hadn't even been counted in November before we heard reports that corporations were already recruiting lobbyists with Democratic connections to carry their water in the next Congress.

That's why it's not enough to just change the players. We have to change the game.

Americans put their faith in Democrats because they want us to restore their faith in government — and that means more than window dressing when it comes to ethics reform.

Last year, I was hopeful that scandals would finally shame Congress into meaningful ethics legislation. But after the headlines faded, so did the enthusiasm for reform. In the end, I found myself voting against the final ethics bill because it was too weak and unresponsive to the obvious need for comprehensive reform.

This time, we must do more.

We must stop any and all practices that would lead a reasonable person to believe that a public servant has become indebted to a lobbyist. That means a full ban on gifts and meals. It means no free travel or subsidized travel on private jets. And it means closing the revolving door to ensure that Capitol Hill service — whether as a member of Congress or as a staffer — isn't all about lining up a high-paying lobbying job. We should no longer tolerate a House committee chairman shepherding the Medicare prescription drug bill through Congress at the same time he's negotiating for a job as the pharmaceutical industry's top lobbyist.

But real reform also means real enforcement. We need to finally take the politics and the partisanship out of ethics investigations. Whether or not the House ethics committee has been covering for its colleagues, the secrecy with which its members have operated has led people to question why legislators who are serving jail time were not caught and stopped by the committee in the first place. It's led people to wonder why Congress cannot seem to police itself.

I have long proposed a nonpartisan, independent ethics commission that would act as the American people's public watchdog over Congress. The commission would be staffed with former judges and former members of Congress from both parties, and it would allow any citizen to report possible ethics violations by lawmakers, staff members or lobbyists. Once a potential violation is reported, the commission would have the authority to conduct investigations, issue subpoenas, gather records, call witnesses, and provide a report to the Justice Department or the House and Senate ethics committees that — unlike current ethics committee reports — is available for all citizens to read.

This would improve the current process in two ways. First, it would take politics out of the fact-finding phase of ethics investigations. Second, it would exert greater public pressure on Congress to punish wrongdoing quickly and severely. Others have proposed similar good ideas on enforcement, and I am open to all options. We must restore the American people's confidence in the ethics process by ensuring that political self-interest can no longer prevent politicians from enforcing ethics rules.

We cannot change the way Washington works unless we first change the way Congress works. On Nov. 7, voters gave Democrats the chance to do this. But if we miss this opportunity to clean up our act and restore this country's faith in government, the American people might not give us another one.

Barack Obama is a Democratic senator from Illinois. He wrote this commentary for The Washington Post.