Donald Trump and Robert Mueller look ready to go to war.
The latest upheaval of the president's legal team comes as Trump has adopted an increasingly hostile posture toward the special counsel, whose investigation has expanded into an examination of whether Trump obstructed justice by seeking to shut down the probe.
Adding further uncertainty is the fact that the President's legal team is in the midst of a shake-up.
In a Tuesday tweet, Trump blasts what he calls a "rigged system".
He also took a cooperative approach to Mueller's requests.
Mueller is investigating Russia's meddling in the 2016 US election, an investigation that includes whether the Trump campaign colluded with Moscow and possible obstruction of justice by Trump, among other things. For the first months of this investigation, it was a time to cooperate and turn things over.
Flood, a former law clerk to the late Supreme Court justice Antonin Scalia, has defended former Vice President Dick Cheney in a lawsuit brought by former Central Intelligence Agency official Valerie Plame and represented President George W. Bush in executive-privilege disputes with Congress - suggesting he is well-versed in the powers of the presidency and may invoke those authorities as the Mueller investigation moves forward.
The replacement of Cobb with Flood may usher in a more adversarial stance toward the Mueller team as Trump's lawyers debate whether to make the president available for an interview with the special counsel and brace for the prospect of a grand jury subpoena if they refuse.
Amid reports that special counsel Robert Mueller has threatened to subpoena President Donald Trump, White House lawyer Ty Cobb joined ABC News' Chief White House Correspondent Jonathan Karl and Political Director Rick Klein on the 'Powerhouse Politics' podcast for a rare interview.
Marc Mukasey, a longtime ally of Giuliani's, also is in talks to possibly join Trump's legal team, according to sources familiar with the matter, though they cautioned that no final decision has been made.
Another attorney whom Trump tried to bring on ultimately passed because of conflicts, and the president two weeks ago added former New York Mayor Rudy Giuliani and a pair of former prosecutors, Martin and Jane Raskin, to work alongside mainstay lawyer Jay Sekulow.
Another brass-knuckle operator, Trump's former campaign manager Corey Lewandowski, told CNN on Wednesday that Trump had exhausted of a team that repeatedly assured him the probe was almost done. If they have an open mind on that, then this is something we would consider.
Michael Hayden, who ran the CIA and the National Security Agency when Mueller helmed the Federal Bureau of Investigation, said the special counsel's character dictated that he eliminate every lead. Everyone knew this day would come when you had to decide whether the President was going to decide to sit down with Mueller or fight a subpoena.
Prosecutors often use interviews with people involved in an investigation to rule out theories or close off lines of inquiry. It has also represented senior White House officials, including presidents. "It would be, max, two to three hours around a narrow set of questions", Giuliani said.
A series of potential interview questions for Trump was leaked to The New York Times earlier this week.
Given the escalating stakes, Trump's tweets on the Mueller probe Wednesday were particularly intriguing.
Trump on Twitter Wednesday promoted a comment from attorney Joseph diGenova describing the questions as an "intrusion" into the president's constitutional powers and saying it would be "outrageous" to ask the president what he was thinking when firing members of the executive branch.
But to prove obstruction of justice, a prosecutor must establish that an act was carried out with corrupt intent.