From left to right, District 8 Democratic congressional candidates David Trone, Kathleen Matthews and Jamie Raskin Credit: Photos via Facebook

As the year-long battle for the Democratic congressional nomination to succeed Rep. Chris Van Hollen approaches its final hours, money has continued to pour into what is already far and away this year’s most expensive House race in the nation.

Total Wine & More co-owner David Trone of Potomac late last week put another $265,000 into his self-funded candidacy, bringing to nearly $2.75 million the amount Trone has donated to himself in the last week of the campaign alone, according to Federal Election Commission (FEC) disclosure filings. Combined with $10 million that he previously reported contributing through early April, Trone—win or lose in Tuesday’s primary—has secured a historical niche as the leading self-funded House candidate ever.

One of his leading rivals, former Marriott International executive Kathleen Matthews of Chevy Chase—who decried Trone’s “nauseating self-spending” in an email to supporters over the weekend—is being aided by a steady flow of contributions from well-heeled backers in the homestretch. In the final three weeks of the campaign, Matthews has reported receiving nearly $47,000 in donations of $1,000 or more apiece, with a half-dozen of these for $2,700—the maximum amount that an outside individual is allowed to give directly to a candidate in a single election.

Meanwhile, Matthews is one of four candidates in the District 8 Democratic race who, on top of donations to their individual campaign committees, is being boosted by “independent expenditures” from so-called Super PACs. Unlike candidates’ personal campaign committees, there is no limit on the amount that this type of political action committee can accept from an individual donor. Super PACs may also take unlimited donations from corporations and labor unions, which are barred from giving directly to candidate campaign committees.

Nearly $400,000 of Super PAC money has been spent so far in the 8th District Democratic primary. Almost three-quarters of this—$291,000—has come from a Super PAC affiliated with EMILY’S List, which has endorsed Matthews; nearly $122,500 of this total has been spent in the past three weeks for a series of pro-Matthews mailings to Democratic households. Three other contenders—state Sen. Jamie Raskin of Takoma Park and former Obama administration officials Will Jawando of Silver Spring and Joel Rubin of Chevy Chase—also are receiving late boosts from Super PACs, which are barred from coordinating their activities with a candidate’s personal committee.

Each of the nine Democratic contenders was required to file a comprehensive report on their contributions and spending with the FEC by mid-April, covering the period from Jan. 1 through April 6. But FEC regulations also mandate that, in the final weeks of the campaign, all contributions of $1,000 or greater to an individual candidate be reported within 24 hours of receipt. In addition, Super PACs and other political action committees must report expenditures of $1,000 or more on behalf of a candidate within a similar time frame.

While a final accounting of contributions and expenditures won’t be filed until mid-May, an examination of FEC data through early April by the non-partisan Center for Responsive Politics (CRP) shows the 8th District contest to be the most expensive House race in the nation this year. Even if the $9 million that the Trone campaign reported spending through April 6 is subtracted, the total of $4.7 million spent by the other Democratic candidates as of that date would still make this the leading House race in the country in spending, according to the CRP.

While Trone had spent more than twice as much as any other House candidate in the country by early April, the CRP analysis put Matthews in 10th place nationally on the list of top-spending candidates, with more than $2.15 million spent. Together, Matthews and Raskin, regarded along with Trone as the frontrunners in the contest, had spent a combined total of nearly $3.4 million by that time.

Throughout the campaign, Matthews’ disclosure reports have shown her drawing heavily on donations from members of the Washington political establishment and the Hollywood entertainment community, and several of her recent contributions continue to reflect that pattern.

Donating $1,000 apiece to Matthews in recent weeks were Carol Browner, who headed the Environmental Protection Agency during the Clinton administration; former Rep. William Delahunt of Massachusetts; and former presidential aide David Gergen, who worked in the Clinton White House after prior stints for three Republican presidents. From the West Coast, producer Norman Lear, creator of All In The Family and other hit comedies during the 1970s, gave $1,000.

Locally, Matthews received contributions from Joshua Rales of Potomac, a wealthy businessman who made an unsuccessful run for U.S. Senate a decade ago, and Richard S. Cohen, who chairs the Willco Cos., a Montgomery County development firm. Each donated the maximum of $2,700.

Raskin received considerably less than Matthews—a total of $8,400—in 11th hour donations from individuals that were $1,000 apiece or more. However, Raskin has received $16,500 in direct donations from traditional political action committees in the past three weeks, twice as much as Matthews.

Raskin, who has had heavy organized labor backing during the campaign, got $5,000 from the PAC of the National Association of Letter Carriers, $2,500 from the American Federation of State, County and Municipal Employees PAC, and $2,000 from the American Federation of Government Employees PAC in direct donations; all three unions had previously endorsed his candidacy. In addition, Raskin received $5,000 from the PAC of the Credit Union National Association.

On top of the $16,500, the PAC of the National Education Association, which also has endorsed Raskin, recently reported $5,000 in independent expenditures on his behalf for billboards.

Matthews reported receiving a total of $7,000 in direct PAC donations during this period, with $5,000 coming from a PAC associated with Deloitte, a worldwide accounting firm that has a Washington-based consulting arm.

The only other candidate to report a significant amount of late contributions of $1,000 or more is Jawando, with a total of $12,700 from individual donors and political committees. Rubin reported just one $1,000 contribution in the final weeks of the campaign, while the remaining four Democratic candidates—state Dels. Kumar Barve of Rockville and Ana Sol Gutierrez of Chevy Chase, former biotech industry official Dan Bolling of Bethesda, and David Anderson, who runs a Washington-based seminar and internship program—have not reported any large contributions during this period.

Jawando—who has emphasized his standing as the only African-American in the contest and, at 33, the only millennial—is also benefitting from a Super PAC called 21st Century Leaders.

Created in late February with the stated intent of supporting multiple candidates, 21st Century Leaders so far has reported just two expenditures totaling nearly $27,000. Both were made last week to an Alexandria, Va.-based firm for mailings to voters on Jawando’s behalf.

The source of funding for this Super PAC is unclear. Its most recent FEC quarterly report, covering the period through March 31, reported no contributions. Whoever has donated during the past month will not be known until 21st Century Leaders files its next required report in mid-July. Rodell Mollineau, a Washington-based political consultant and a former aide to Senate Democratic Leader Harry Reid of Nevada, is listed as the committee’s treasurer.

Another Super PAC, Mayday—formed two years ago to advocate for reform of the campaign finance system—first injected itself into the District 8 race last fall, endorsing Raskin and criticizing Matthews. It re-emerged last week, reporting $3,500 in digital ad expenditures on behalf of Raskin, a constitutional law professor who has vocally advocated rolling back the 2010 Supreme Court decision, Citizens United vs. FEC, that opened the way for creation of Super PACs.

While Mayday last fall declared its intention to raise $100,000 to boost Raskin’s candidacy, last week’s digital ad brings its total expenditures on behalf of Raskin to barely $4,500. Raskin also has been the beneficiary of more than $20,000 in mailings in recent weeks by the Freethought Equality Super PAC. The latter is the political arm of the American Humanist Association, which defends and promotes atheism. The amount spent is well short of the $50,000 an official of the Freethought Equality Super PAC recently said the group planned to spend on Raskin’s behalf before the primary.

Rubin is getting help from a Super PAC, A New Voice for Maryland, funded entirely by a friend, William Benter, who runs a Pittsburgh medical services firm. To date, it has spent about half of the $100,000 that Benter contributed, including about $11,000 in the past week for digital advertising and a robocall—in which 8th District Democratic voters heard an endorsement of Rubin by actor Michael Douglas.

By far the biggest Super PAC operating in Montgomery County this spring is not in the 8th District but in the neighboring 6th, where national security consultant Ami Hoeber is seeking the Republican nomination against Democratic Rep. John Delaney. Maryland USA, a Super PAC formed specifically to boost Hoeber, has spent a total of more than $1.45 million—floated by $2.1 million in contributions by Hoeber’s husband, Mark Epstein, a former technology company executive.

In the last two weeks, Maryland USA has spent $600,000 on TV and radio ads, on top of more than $150,000 in digital advertising and direct mail, to boost Hoeber’s bid in the eight-way contest. Her leading rivals for the nomination are Washington County Commissioners President Terry Baker, businessman Frank Howard of Laytonsville, and state Del. David Vogt of Frederick County. Howard last week received the endorsement of Dan Bongino, the 2014 Republican nominee in the 6th District—which stretches from Potomac and Gaithersburg more than 200 miles into far western Maryland.

The heavily Democratic 8th District is based primarily in Montgomery County, but extends north to the Pennsylvania border. Trone is the only District 8 candidate with TV spots running on Baltimore as well as Washington broadcast stations; the Baltimore buy aimed at voters in Carroll and Frederick counties, where about 18 percent of the district’s more than 240,000 registered Democrats reside.