Top contenders for the Democratic presidential nomination, including U.S. Sens. Kamala Harris and Elizabeth Warren, turned to Perkins Coie for legal counsel in recent months as they ramped up their bids to take on President Donald Trump in next year's election, according to new campaign finance disclosures.

After paying the firm $80,000 in the first quarter of the year, Warren's campaign sent Perkins Coie an additional $240,000 between April and June, the new disclosures show. Several of Warren's rivals for the Democratic nomination joined her in hiring Perkins Coie in the three-month period ending June 30.

Harris's campaign paid Perkins Coie more than $90,000, according to the disclosures. Marc Elias, the head of Perkins Coie's political law practice, is reportedly serving as the Harris campaign's general counsel. In 2016, Elias served as the general counsel to Hillary Clinton's campaign, and his firm has long been one of the closest-tied to Democratic presidential campaigns.

Two other U.S. senators, Kirsten Gillibrand of New York and Amy Klobuchar of Minnesota, each spent more than $85,000 on Perkins Coie's legal services. And a pair of former governors from Western states, Jay Inslee of Washington and John Hickenlooper of Colorado, both hired the firm, with Inslee's campaign paying it nearly $110,000 in April. Hickenlooper's campaign paid Perkins Coie about $4,000 in early June.

Julian Castro, a former Obama administration housing secretary, paid the firm about $23,000 in April, according to his campaign's disclosure.

Taken together, the new disclosures paint a picture of the campaign business major U.S. law firms have captured in the Democratic primary. Perkins Coie stood out as the top earner among law firms, hauling in nearly $750,000 from top Democratic candidates in the second quarter.

But it was not the only law firm advising more than one candidate.

Utrecht, Kleinfeld, Fiori, Partners, a Washington-based law firm specializing in election and campaign finance law, advised Castro, Inslee and U.S. Sen. Michael Bennet, a Colorado Democrat and former associate at Wilmer Cutler Pickering Hale and Dorr. Bennet's campaign paid the firm $15,000. Inslee and Castro's campaigns paid the firm $40,000 and $45,000, respectively, between April and June.

Joe Biden's campaign paid Covington & Burling nearly $68,000 in June, a month after the former vice president launched his campaign. The National Law Journal had previously reported that Covington partner Robert Lenhard, a former chairman of the Federal Election Commission, was advising Biden's campaign.

Jenner & Block Jenner & Block offices in Washington, DC. Photo: Diego M. Radzinschi/NLJ

Of the leading Democratic candidates, South Bend, Indiana, Mayor Pete Buttigieg spent the most on legal services, shelling out more than $320,000 on Jenner & Block. Previn Warren, a Washington-based intellectual property partner at the firm who attended Harvard with Buttigieg, is serving as the campaign's general counsel.

Other candidates divided their legal spending among several firms. Former U.S. Rep. John Delaney, a Maryland Democrat, paid a combined $30,000 to Arent Fox, Ballard Spahr and Cozen O'Connor, according to his campaign finance disclosure for the second quarter.

U.S. Sen. Bernie Sanders, a Vermont Democrat, reported about $260,000 in legal fees, most of it going to Garvey Schubert Barer. Brad Deutsch, a Garvey Schubert partner in Washington, served as Sanders' campaign general counsel in 2016. The Sanders campaign spent another $23,000 at the Washington labor and employment firm Peer, Gan & Gisler.

Andrew Yang's campaign paid $10,000 to Dentons between May and June, and the campaign of former U.S. Rep. Beto O'Rourke of Texas spent $64,114 on legal services from the Washington political-law firm Sandler Reiff Lamb Rosenstein & Birkenstock. U.S. Rep. Tim Ryan of Ohio hired Venable, paying the firm about $8,500 between May and June, as U.S. Rep. Tulsi Gabbard divided her campaign's $7,500 in legal spending between Bergeson and Blank Rome.

New York Mayor Bill de Blasio's campaign, which reported raising a paltry $1.1 million in the second quarter, said it paid Washington's Trister, Ross, Schadler & Gold nearly $3,500 for legal services.