“This [race] is actually about electing Democrats whose financial interests are aligned with their communities’ interests,” Ocasio-Cortez told The Intercept in May.

Given this history, any job Crowley chose that was related to lobbying would have been easy bait for Ocasio-Cortez’s allies. When it was reported earlier this week that Crowley, along with former Republican Representative Bill Shuster, will be joining the lobbying and law firm Squire Patton Boggs, some members of Ocasio-Cortez’s camp say they weren’t surprised. “It exposes what AOC talks about a lot,” says Arthur Tarley, a progressive activist who volunteered with Ocasio-Cortez’s 2018 campaign. “It neatly fits in with the narrative that most politicians, whether it’s in Washington or Albany or wherever, are in it for themselves, for their donors, for those with means.” A representative for Crowley declined to answer questions about his career transition.

Crowley won’t be alone this year in moving through the so-called revolving door. At Squire Patton Boggs, he and Shuster will join other prominent former lawmakers such as former House Speaker John Boehner of Ohio, former Senate Majority Leader Trent Lott of Mississippi, and former Senator John Breaux of Louisiana. And dozens of other members who left Congress last month have either headed to lobbying firms or are starting their own, according to reporting from Politico.

In fact, lobbying is the single most popular career choice for retiring members of Congress. Of the nearly four dozen lawmakers who left office after the 2016 election, one-fourth stayed in Washington, and one in six became lobbyists, according to an analysis by The Atlantic. The job allows former lawmakers familiar with the players and processes of government to use their expertise to their, and their companies’, advantage. The transition to lobbying is called “cashing in” for a reason: Members of Congress, who typically make about $174,000 a year, can make hundreds of thousands—even millions—working at lobbying firms.

Read: An exodus from Congress tests the lure of lobbying

Of course, former lawmakers need to make a living, too. And many members turned advocates say that lobbying allows them to continue pushing for the causes they believe in—including Crowley. “Serving in Congress was an honor of a lifetime and I look forward to working on many of the same issues in this new role,” the Democrat said in a press release.

Lobbyists can also serve something of a public service: Members of Congress and their staff don’t have the time or capacity to become experts in every issue they encounter. “Lobbying is the world’s second-oldest profession. It’s always going to be there,” says Zach Wamp, a former U.S. representative from Tennessee and the co-chairman of Issue One’s ReFormer’s Caucus, a collection of 200 former lawmakers who advocate to reduce the influence of money in politics. “If your child is killed by a drunk driver, and you start a group called Mothers Against Drunk Driving, you of course want the best lobbyist there to talk to lawmakers about this issue,” Wamp says.