In response to a plan that Bernie Sanders offered this week to break up Wall Street banks, former top Obama economic adviser Austan Goolsbee took to Twitter to criticize the Vermont senator for targeting large financial institutions and being politically unrealistic.

But Goolsbee is hardly an unbiased observer. Since leaving government, he’s become a valuable tool for Wall Street.

Here are some of his tweets:

Goolsbee is now a partner at 32 Advisors, a financial strategy and government relations firm that works with Wall Street. He touts, on his company’s website, a 2014 CNBC profile where he was dubbed “hedge funds’ secret weapon.”

In that piece, post-government Goolsbee was praised by firm portfolio manager Dan Arbess for his “strong informal ties” to the Obama administration. “Maintaining a regular dialogue with Austan helps us better understand the administration’s economic policies, and economic policy decisions debated in other parts of the government, and maybe even exchange views in a helpful way in the other direction, too,” said Arbess.

Skybridge Capital founder, Anthony Scaramucci, who was a member of Mitt Romney’s presidential finance committee, said that Goolsbee provided “thoughtful” advice on policy topics being debated in Washington.

“He has the ability to apply his practical knowledge of the world and his insider understanding of the personalities that are driving key policy,” Scaramucci is quoted as saying in the article. “Austan’s advice and guidance have been priceless.”

Goolsbee told CNBC that he was recruited to the firm by then-UBS President Robert Wolf, who told him, “Look, you know a lot about economics, the Fed, the international economy, how policy is made and affects things. On Wall Street and at big industrial companies and investors and a bunch of people, there’s a lot of demand for that.”

So it’s no surprise that Goolsbee is critical of Sanders. Sanders is biting the hand that feeds him.