George Conway, Spouse of Top Trump Counselor, Takes White House to Task on Twitter.

“He’s one of my most conservative friends,” said Lisa Blatt, a lawyer who has known Mr. Conway for six years. “He hasn’t changed that much to me since before Trump was even a candidate.”

With his Clinton-era background, Mr. Conway understands how volatile political climates work. Now at the white-shoe law firm Wachtell, Lipton, Rosen & Katz, he may have a better understanding than most of the political maelstrom that faces the White House legal team, especially as midterm elections approach. But he has in recent years focused on securities and antitrust cases, not criminal or campaign-finance law.

“George would be spectacularly qualified to give legal advice to just about anyone on any topic,” Mr. Grundfest said. Asked whether Mr. Conway’s experience in Washington suited the president’s current needs, Mr. Grundfest said, “My neighbor has a poodle smarter than some of the people on Trump’s legal team.”

(Mr. Grundfest stressed that he had picked an intelligent dog breed.)

Still, David Lat, a friend and founder of the legal news website Above the Law, said in an email that Mr. Conway “has a practical understanding of what it’s like to be walking the legal tightrope while in the public spotlight.” At the dawn of the Trump administration, Mr. Conway took himself out of the running to lead the Justice Department’s civil division, citing family considerations.

Mr. Conway said in a statement last year that it was “not the right time for me to leave the private sector and take on a new role in the federal government.” He added, “Kellyanne and I continue to support the president and his administration, and I look forward to doing so in whatever way I can from outside the government.”

In the months since, the Conways have appeared to adjust to life in Washington, though they are hardly glued to each other’s side. During the weekend of the White House Correspondents’ Association dinner, for instance, Ms. Conway attended a dinner hosted by David Bradley, the founder of Atlantic Media, solo. She later joined Mr. Conway at a party at the British Embassy.

Mr. Conway’s tendency to share opinions critical of the Trump administration has warranted more attention than his movements in Washington, but he has offered little hint about whether it suggests a deeper political discord. In an interview last year with The Washington Post, Mr. Conway described himself as having “contrarian tendencies” and a willingness to subvert expectations.