Why can't Donald Trump keep a lawyer?

Cobb in the offices of his law firm Hogan & Hartson in Denver Jan. 16 2004. Cobb is a distant relative of baseball legend Ty Cobb

Special Counsel Robert Mueller has finally met "his match" - and now America will witness a "fair fight" between President Trump's legal team and Mueller, who has been leading an investigation into alleged "collusion" between Russian Federation and the Trump campaign for almost a year now.

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.

White House press secretary Sarah Huckabee Sanders said that Cobb had been discussing the decision for weeks and would retire at the end of May and that Flood would be joining the White House staff to "represent the president and the administration against the Russian Federation witch hunt".

One person familiar with the legal team said Flood's selection came in part because the investigation has reached a pivot moment.

The administration has reportedly been courting Flood since last summer, but was unable to secure him then on account of his dislike for Trump outside lawyer Marc Kasowitz, who has since left the President's employ.

Mueller's team has recently discussed subpoenaing President Trump, according to the Washington Post.

The arrival of Emmet Flood is a signal that Mr. Trump is girding for a battle with special counsel Robert Mueller.

Mr. Flood is himself seen as a prospective replacement for that job, potentially providing a smooth exit ramp for Mr. McGahn, who has clashed privately with Mr. Trump and whose departure has always been rumored.

The lawyer leading USA president Donald Trump's response to the special counsel investigation into Russian interference in the 2016 election is to resign.

Trump previously denied the reported shakeup was in consideration, tweeting "wrong" in March in response to a story from the Times that he was looking to add Flood to his team dealing with the Mueller probe.

McGahn and Flood declined to comment.

Cobb counseled cooperation with Mueller and arranged document transfers and interviews with top White House officials that were completed by January.

Cobb's departure was not unexpected given that he had largely wrapped up his duties of providing documents to Mueller and shepherding aides through voluntary interviews with the special counsel's team.

"You know Giuliani can poke this lion as much as he wants, but you have to be careful about what you ask for", said Jonathan Turley, an impeachment expert and law professor at George Washington University. "Emmet is a quintessential wartime consigliere".

In private conversations, Trump has occasionally invoked his late attorney Roy Cohn, a hard-charging figure who taught him to punch back at enemies.

Giuliani's comments to the Post suggest that Trump's legal team hopes to limit the scope of the questions and the duration as conditions of the potential interview.

In the past month, however, Trump has hardened against the idea after FBI investigators working with federal prosecutors in Manhattan executed a surprise search warrant of his personal attorney Michael Cohen's office and residences.