Washington (CNN) Pushed up against the basement wall of the Democratic National Committee headquarters stands a drab, four-drawer file cabinet -- an infamous reminder of political opposition research pressed to the criminal extreme.

The file cabinet was in the DNC's Watergate office on June 17, 1972, the fateful day when five people were arrested for burglary -- a crime that would lead to the resignation of President Richard Nixon.

Nearly 43 years later, a team of 20 Democratic staffers are working three floors above where the filing cabinet now stands, compiling opposition research on the more than two dozen Republicans who have expressed interest in running for the presidency. Just blocks away, a team of Republican researchers is doing the same thing -- with a specific emphasis on former Secretary of State Hillary Clinton. The difference in what the DNC and RNC aides are doing now and what happened in 1972 is that today's research activities are legal.

The process of gathering and unearthing opposition research on individuals has evolved over the years, but the goal remains the same: find embarrassing information that can be used against your opponent or create an unflattering narrative that will turn voters off.

The folklore of political opposition research suggests that it can be dangerous work including having operatives go "dumpster diving" in search of information. DNC research director Lauren Dillon said that is simply not true.

"Believe it or not, we don't go through people's trash," she said. "But we do find a lot of good stuff."

Where does this "good stuff" come from? Well, if you are a politician it may come from a state archive, voting history and public statements as well as newspaper stories, business filings, campaign donations and social media accounts. Political novices face the same scrutiny, without, of course, a public record.

DNC communications director Mo Elleithee said the most effective opposition research is not the "gotcha moment," but often rather the creation of a storyline that is damaging to the opponent.

"It's not about finding a silver bullet," Elleithee said. "If we find one, great, we'll be ready. But campaigns aren't won or lost all the time with a 'macaca' moment or a Todd Akin moment. What we're focused on is just connecting the dots in order to tell a story about each of these folks, hold them accountable for their records, and make sure that voters understand the other side and their real record."

Akin is a former congressman whose controversial comments about rape helped lead to his defeat in the 2012 Missouri Senate race. "Macaca" was a little-known slur used by Virginia Sen. George Allen to describe a Democratic operative of Indian descent in his 2006 losing Senate campaign.

Elleithee, specifically points to the DNC's strategy in the fall of 2013 to focus on Bridgegate -- an embarrassing story for New Jersey Gov. Chris Christie about lane closures that continues to dog him to this day.

Creating individual dossiers about the potential Republican presidential candidates began shortly after President Barack Obama won a second term, Elleithee said. Dillon, a key researcher on Obama's campaign team, was hired to oversee the DNC's research efforts that are divided into three areas: 2016, video and rapid response.

While some members of the Democratic research team spend a good part of their day watching speeches and searching for public comments made by each potential GOP candidate, others comb through state and federal records, news stories, business dealings, campaign donations and social media accounts in search of damning or embarrassing information.

One year ago, the DNC sent a team to Tallahassee to gather any files the Florida Democratic Party had about former Gov. Jeb Bush and Sen. Marco Rubio, two Republicans who are weighing presidential bids.

"Out of that meeting we came home with these boxes that have been sitting in a back room at the Florida Democratic Party offices," said Elleithee, as he pointed to several boxes stacked up outside a row of cubicles. "That's just old Jeb Bush material. No one else has this material."

As the DNC and its counterpart, the RNC, create opposition research files on the candidates, outside independent groups are doing the same thing. But the difference is that the national committees are the only organizations allowed to coordinate with the respective presidential candidates.

"We're the only ones who can actually communicate with the eventual nominee, and we're really the ones who are going to help define who the Republican candidates are long before we have a nominee," Elleithee said. "But once we do, we'll be working hand and glove with them to make sure that the work that we've been doing for the past couple of years is helpful to their eventual campaign."

Expect the RNC to do the same.