If former Connecticut Sen. Joseph Lieberman becomes the new director of the Federal Bureau of Investigation, the agency will be run by one of America’s most outspoken supporters of mass surveillance. Lieberman has called for aggressive measures to crack down on government leaks, has tried to weaken whistleblower laws and has supported legislation that critics say would punish journalists. As FBI chief, he would be in a position to act on President Donald Trump’s reported desire to jail journalists who publish leaks of classified information.

Lieberman is now reportedly the frontrunner for the FBI job. On Wednesday, after he met with Trump to discuss potentially taking fired FBI Director Jim Comey’s job, the president signaled his preference for the former Connecticut senator, aides told Politico.

Lieberman currently works at Trump’s longtime law firm, Kasowitz, Benson, Torres and Friedman — a link prompting assertions that he would have an inappropriate conflict of interest for someone who would lead a law enforcement agency amid an investigation into the Trump administration’s contacts with foreign governments. Lieberman has in recent months publicly praised Michael Flynn — one of the key Trump figures in the law enforcement investigation — and his political group has previously labeled Trump a bipartisan problem-solver.

Beyond his potential conflicts complicating the probe, Lieberman could also be a controversial nominee due to his positions on the law enforcement power that he would be in control of as FBI director.

During his time in the Senate, Lieberman was one of the most ardent supporters of expanding government surveillance.

In December 2010, for instance, Lieberman successfully pressured Amazon.com and the data visualization site Tableau to stop publishing charts that included materials believed to have originally been posted by WikiLeaks. His move was criticized by transparency groups as an affront to the First Amendment.

In 2009, as Chairman of the Senate Committee on Homeland Security and Government Affairs, he joined with ranking member Susan Collins in pushing a bill that would weaken protections for whistleblowers in the FBI. One whistleblower advocacy group published a letter saying the legislation “will set whistleblower protections back 30 years for hundreds of thousands of federal employees.”

As the New York Times recently reported, Trump told Comey he wanted the FBI to jail journalists who publish classified information — and Lieberman has sponsored legislation on that issue. His 2010 bill to amend the Espionage Act, the Reporters Committee on Freedom of the Press wrote, “would make it a crime to publish classified information concerning the human intelligence activities of the United States or any foreign government, or concerning the identity of a classified source or informant of an element of the U.S. intelligence community.”

After voting for the 2001 Patriot Act, which originally expanded government surveillance powers after the Sept. 11, 2001 terrorist attacks, he joined Republicans in supporting a measure to reauthorize the law in 2009.

In 2007, Lieberman urged the United States to follow Britain and expand its surveillance programs. He has continued to publicly defend a National Security Agency program that collects vast troves of phone and Internet data.

That same year, he was one of 17 Democrats who joined Republicans in voting in favor of an amendment of the Foreign Intelligence Surveillance Act giving the U.S. authority to monitor the calls and emails of Americans communicating with people outside of the country without a warrant.

"We're at war. The enemy wants to attack us," Lieberman reportedly said in the Senate, ahead of the vote. "This is not the time to strive for legislative perfection."