Since 2011, the Democratic National Committee has made 56 payments totaling more than $4.5 million to the U.S. Treasury, most of which paid for catering at “Reservation #1,” the National Park Service’s terminology for the White House grounds.

On the campaign trail in 2007, Barack Obama decried the Bush administration for over-politicizing his office, telling a crowd in Manchester, N.H., that “the days of using the White House as another arm of the Republican National Committee are over.” But a new Sunlight analysis of campaign finance records from the Democratic National Committee (DNC) finds party operatives have made frequent use of the White House during Obama’s tenure.

Each of the transactions were earmarked to Dennis Freemyer, the former deputy director of the Executive Residence and deputy chief usher at the White House, and addressed to a National Parks Service office in Riverdale, Md. The White House grounds are technically part of the Parks Service.

The DNC did not return multiple calls and e-mails from Sunlight inquiring about the payments, but the outlays appear to have gone towards social gatherings at the White House like the annual Christmas party, which is traditionally paid for by the party in office.

The biggest bashes apparently occur during the holiday season, in fact. Data from the Federal Election Commission show large spikes in DNC payments to the Treasury each year in October, November or December, with payments ranging from $500,000 to just under $1 million.

Sunlight also found numerous other catering payments, ranging from $20,000 to $60,000, that did not take place in the last three months of the calendar year.

You can see a visualization of those disbursements below, or see the underlying data here.

White House visitor logs released by the Obama administration show thousands of individuals set foot on White House grounds for December holiday parties. Linking the other payments to specific events, however, is more difficult.

Federal law requires that political events at the first residence be paid for in advance and a search through the visitor logs finds only four events during that time period that were marked as partisan gatherings. Only one of those occurred in 2014: a June 6 reception for the DNC Executive Committee hosted by Jill Biden, the vice president’s wife. But, as the FEC data indicates, there have been many more events than that.

A White House spokesperson would not comment on specific questions about holding partisan events on White House grounds or visits of donors’ and DNC officials. A review of some of the thousands of names of visitors finds many individuals who have contributed financially to the DNC and the Obama campaign interspersed with other attendees at large events in the executive mansion.

White House visitor logs include an enormous numbers of events, including one-on-one meetings and receptions for hundreds of invited guests. On any given day, there are multiple events, the vast majority of which are official business, but which sometimes include among attendees DNC officials, donors and bundlers.

For example, on May 1 of last year, the visitor logs show that among the hundreds of people attending events were Stephen Bittel, a Miami real estate developer and Democratic bundler who formerly served as the vice-chair of the National Jewish Democratic Council, and Leslie Saiontz, chair of Teach for America and a Democratic donor who hosted a fundraiser for Obama in 2013. The same event included representatives from the National Education Association, a big political supporter of Democrats, operators of magnet schools and Frank Biden, Vice President Joe Biden’s brother and a former head of a for-profit Florida charter school system.

On the next day, the President met with Shekar Narasimhan, a member of the President’s Advisory Commission on Asian Americans and Pacific Islanders (AAPI), along with Democratic Reps. Judy Chu, and Mike Honda, both of California, and several other Asian American civic and religious leaders. Narasimhan, a former chair of the DNC’s Indo-American council, has donated more than $350,000 to Democratic candidates since 1999. A White House press release indicates the president met with AAPI leaders to discuss immigration reform.

The visitor logs can’t be used to determine whether the events these individuals — or those attended by thousands of others on other days — were partisan affairs paid for by the DNC or, more likely, nonpolitical events to which the White House invited some donors, bundlers and DNC officials.

The Hatch Act precludes most public officials from engaging in partisan activity in federal buildings, though certain executive branch officials may engage in it while on the job, so long as they do not use taxpayer funds to do so and do not solicit political contributions. The president and vice president are not covered by the act.

Occupying the White House has long given presidents a powerful tool for raising money — including Bill Clinton’s political operation, which invited donors to have sleepovers in the Lincoln Bedroom.

A Sunlight review of FEC reports from the Republican National Committee from 2003 to 2006 finds that the RNC paid the U.S. Treasury a little under $3.6 million for catering, decorations and meetings costs over that time. As with the DNC, the largest expenditures took place around the holidays, but also had some large catering bills in February, March and May over the years. (The RNC data is available here.)

The Bush White House did not stop there in making use of the White House for political purposes. A 2011 report from the independent Office of Special Counsel found that its Office of Political Activity had acted as a de facto “political boiler-room,” and that “OPA employees routinely worked with the RNC to strategize about how best to utilize administration assets to help targeted candidates” in the 2006 mid-term elections.

The Obama administration decommissioned the OPA in 2011, days before the OSC report was released, but later established a similar office, the Office of Political Strategy and Outreach, in January 2014. And big contributors to Obama’s campaigns have had access to the White House all along, as the bulk data on White House visits, released in response to a lawsuit filed by a pair of Washington good government groups, have shown.

A 2009 investigation by the Washington Times used the visitor logs to show frequent White House visits by major Democratic donors and DNC documents that appeared to offer access to senior administration officials in exchange for donors’ maximum campaign contributions.

More recent reports by the Associated Press, the New York Times, Sunlight and other outlets have noted that top tier campaign and super PAC donors have made frequent appearances at the executive mansion and its surrounding offices.

In 2009, in response to questions raised by the Washington Times reporting on White House access afforded to donors, then-White House Press Secretary told reporters that “contributing doesn’t guarantee a trip to the White House, nor does it preclude it.”

Full disclosure: The author formerly interned at the Democratic National Committee for four months in 2012. As part of the application, the author submitted an essay, which the DNC awarded with a $1,000 stipend.