Shortly before Election Day, a Stanford graduate student reported that the campaign Web sites of President Obama and Republican challenger Mitt Romney were “leaking” personal information about their supporters through careless data handling.

Had it been Facebook and Google, a federal investigation might have ensued, and the companies could have suffered significant public relations setbacks and perhaps fines. But the Federal Trade Commission, the government agency most focused on personal privacy, has no jurisdiction over campaigns or political groups.

That is a small example of what privacy advocates say is a big problem with efforts to protect personal information in the United States: The politicians are not guarding the chicken coop. They are the foxes.

Obama’s sophisticated use of Big Data gave him a crucial edge in what, based on popular support alone, should have been a close election. Republicans are desperate to catch up. But it’s not clear who is positioned to protect voters’ rights at a time when politicians from both parties increasingly build their campaigns on the insight that commercial data brokers provide.

Washington has a community of professional privacy advocates at places such as the American Civil Liberties Union, the Electronic Privacy Information Center and the Center for Digital Democracy. Jeff Chester, executive director of the Center for Digital Democracy, said he approached lawmakers from both parties to express his concerns long before the election but got nowhere.

Some of the data gathered by the Democrats during the recent presidential campaign.

“Maybe we’re digital Don Quixotes,” Chester said. “There was a lack of interest, not surprisingly.”

People routinely tell pollsters that they’re concerned about online privacy, and Chester and his colleagues in the field count some allies on Capitol Hill and in the White House. The FTC under Chairman Jon Leibowitz and David Vladeck, head of its Bureau of Consumer Protection, have made the agency far more aggressive on consumer privacy generally — even if political campaigns are beyond their reach.

Yet overall, the laws in the United States are much less strict than they are in Europe, where there are tight limits on what personal information can be collected and how long it can be kept. Companies caught crossing the line can provoke furious backlashes among their users.

The American political landscape, by comparison, is amorphous when it comes to privacy. There are widespread concerns on both the right and the left but no single, coherent constituency demanding greater protections.

For all the talk in recent years about online privacy, data-hungry Google remains the most popular search engine and data-hungry Facebook the most popular social media site. Both worked closely with the campaigns and have growing lobbying operations in Washington. Google Executive Chairman Eric Schmidt was a regular visitor at Obama’s Chicago campaign headquarters, those who worked there said, offering advice to the campaign’s data-savvy technologists.

Privacy advocates say the tide will eventually turn, when Americans truly understand the extent to which their information is collected and traded. A recent poll by the University of Pennsylvania’s Annenberg School for Communication found that nearly two-thirds of people would be less likely to support a candidate who bought data about voters’ online activities and used it to tailor political ads.

“People still don’t quite understand this stuff,” said Joseph Turow, the lead researcher on the Annenberg poll. He said politicians are “hoping people will, quote-unquote, get used to it.”