ON A rainy afternoon, two sharply dressed men talk business and clink $40 glasses of wine at the Trump International Hotel, a few blocks from the White House. The recently opened hotel, which offers $65 steaks and a $100 cocktail made with raw oysters and caviar, has become popular among cabinet members, lobbyists and curious journalists. It would seem the swamp monsters, whom President Donald Trump once pledged to purge, are not doing too badly.

Lobbying expenses for the first six months of the year amounted to $1.67bn—the most since 2012—according to the Centre for Responsive Politics (CRP), a watchdog. The figure might have been even higher if Republicans had managed to convert their undivided control of Congress and the White House into legislative accomplishments. Instead, repeated attempts to reform Obamacare ran into the sand and the prospects for tax reform are uncertain.

Yet, strangely, the number of registered lobbyists has fallen sharply. In the second quarter of 2017 there were just 9,791—a third fewer than the 15,000 milling about K Street and other lobbyist haunts ten years ago. The number of dollars spent per registered lobbyist increases every year. Either the price of persuasion has shot up, or people are not being counted properly.

The answer is almost certainly the latter, and the man to blame is Barack Obama. The last president, who had promised to “take the blinders off the White House”, instituted strict rules limiting lobbyists from serving in his administration. Some influencers went underground, dodging registration requirements by not spending more than 20% of their time working for any single client. By one estimate, the official rolls capture only one in two lobbyists. Of the 2,100 lobbyists in 2016 who did not register in the first quarter of 2017, 58% stayed at the same company, according to the CRP. Many still seemed to be working to influence federal policy.

Purging lobbyists may be as hard as eradicating illegal drugs, and for the same reason: strong demand. So argue Lee Drutman and Steven Teles, two academics, who reason that Congress is increasingly incapable of creating policies. The number of workers in the Congressional Research Service, Congressional Budget Office and Government Accountability Office, the internal information services that provide unbiased reports to members, has dropped by 40% since 1979 even as legislation has grown more complex. Paid influencers, including those without the word “lobbyist” on their business cards, fill the gap.

Since Congress is unlikely to hire many more wonks, the Trump International Hotel will continue to sell fishy cocktails and pricey rooms. Mr Trump’s company had expected to sustain $2m in losses after opening the posh project in the first four months of 2017. Instead, it turned a $2m profit.