Principal Deputy Solicitor General Jeffrey Wall, who recently urged an appellate court to order the dismissal of the federal prosecution of Michael Flynn, soon will step into the job of the government's top lawyer before the U.S. Supreme Court.

With the Wednesday announced departure of U.S. Solicitor General Noel Francisco, Wall, 44, will become acting solicitor general until he or someone else is appointed and confirmed to the position. The Justice Department said the resignation of Francisco, a former Jones Day partner, is effective July 3.

"Solicitor General Noel Francisco has represented the United States superbly before the Supreme Court for the past three Terms," U.S. Attorney General William Barr said in a statement. "Arguing before the Court 17 times on behalf of the federal government, he has been a principled and persuasive advocate on issues ranging from the separation of powers to religious liberty to vigorous enforcement of federal immigration law."

Prior to joining the office of solicitor general, Wall was co-chair of the appellate litigation practice at Sullivan & Cromwell. Earlier in his career, he was an assistant to the solicitor general for five years. Wall was appointed principal deputy solicitor general in March 2017. That position is commonly known as the "political" deputy who flags cases with major political overtones and sometimes defends the office's position when it is at odds with the administration.

Wall has argued 27 cases in the U.S. Supreme Court, including six in the current term. His most recent argument was last month in the case Trump v. Mazars. He argued as an amicus party supporting President Donald Trump's refusal to turn over his financial documents to three U.S. House committees. He also argued for the government in this term's abortion case, supporting Louisiana's regulation of abortion physicians, in June Medical Services v. Russo. The case is pending a decision.

At the Supreme Court's lectern, Wall has a polished and earnest style of argument. He never hesitates in his responses to rapid-fire questions and hypotheticals from the justices. A graduate of the University of Chicago Law School, Wall is a former clerk to Justice Clarence Thomas during the 2004-05 term and to Judge J. Harvie Wilkinson of the U.S. Court of Appeals for the Fourth Circuit.

Speaking at Princeton University last year, Wall asserted there had been a significant power shift towards the judiciary in recent years. That shift and other trends converged, he added, in legal challenges to nearly every executive branch policy.

"It's only going to get worse," he said, and will result in a scenario where "we effectively disable the executive from acting."

"The tools you forge today will be used against you tomorrow," he added. "I don't think Republican lawyers in red states will forget this when a Democrat takes the White House."

In the same talk, Wall described serving in the solicitor general's office as "truly a humbling experience. We have the best lawyers in the country. I love that because you really have to check your ego at the door."

Wall follows a long line of acting solicitors general, including his current boss Francisco, who served in that position briefly before his Senate confirmation as solicitor general in September 2017.

Jenner & Block partner Ian Gershengorn was principal deputy solicitor general during the Obama administration and became acting solicitor general when then-solicitor general Donald Verrilli Jr. left the job. He remained in the job until Trump took office as president. Verrilli is now a partner at Munger, Tolles & Olson.

During the Obama administration's first term, Georgetown University Law Center's Neal Katyal, now a partner at Hogan Lovells, was principal deputy solicitor general to then-Solicitor General Elena Kagan, and he became acting solicitor general when Kagan was elevated to the Supreme Court in 2010, and he served until June 2011.

Latham & Watkins partner Gregory Garre, head of the firm's Supreme Court and appellate practice, was principal deputy solicitor general during the George W. Bush administration and became acting solicitor general after the resignation of now-Kirkland & Ellis partner Paul Clement. Garre was confirmed unanimously as solicitor general in October 2018.

Francisco was appointed principal deputy solicitor general and acting solicitor general on the same day and served from Jan. 23, 2017, until March 10, 2017, when Trump nominated him to be solicitor general. At that point, Francisco became a senior adviser to the associate attorney general until his Senate confirmation.

Noel Francisco U.S. Solicitor General Noel Francisco. (Photo: Diego M. Radzinschi / ALM)

During his tenure, Francisco defended myriad Trump administration policies in the Supreme Court, including the controversial travel ban on predominantly Muslim nations and a citizenship question on the 2020 census. Awaiting decisions by the Supreme Court are his arguments supporting Trump's defiance of a state grand jury subpoena for his tax records and defending the elimination of the Deferred Action for Childhood Arrivals program for so-called Dreamers.

Francisco also worked with other Trump Justice Department officials to challenge nationwide injunctions by federal judges and has twice brought the issue before the Supreme Court, including in the current term.

In his resignation letter, Francisco said that, after three Supreme Court terms as solicitor general, he felt it was time to return to the private sector and spend more time with his family. He personally argued 17 Supreme Court cases as solicitor general.

Barr said Francisco's "skilled advocacy has been instrumental to historic victories on behalf of the president's national security authority, the free speech rights of public employees, and property owners' access to federal courts, among many other significant accomplishments."

Francisco's announcement is the third in the Justice Department in recent days. Jody Hunt, head of the department's civil division, said he will step down July 3. Last week, Brian Benczkowski, head of the department's criminal division and a former Kirkland & Ellis partner, said he is stepping down effective July 3 after two years in office.