Jonathan Ernst | Reuters
President Donald Trump delivers remarks on the U.S. opioid crisis, at Manchester Community College in Manchester, New Hampshire, March 19, 2018.
Another key exception for attorney-client privilege regards whether a lawyer and his or her client colludes on potential crime or fraud.
"The purpose of this exception is to assure that the secrecy between lawyer and client does not extend to obtaining advice in furtherance of contemplated or ongoing criminal or fraudulent conduct," attorney and MSNBC contributor Danny Cevallos wrote in a legal analysis for NBC News.
Cohen is reportedly being investigated for crimes possibly related to bank fraud and campaign finance violations. The FBI is seeking evidence related to the payment Cohen made to porn star Stormy Daniels on the eve of the 2016 presidential election.
The raids came after federal prosecutors in New York City obtained a search warrant following a referral from special counsel Robert Mueller, Cohen's lawyer said.
Trump's tweet comes after a White House event Monday evening where he ripped into the entire special counsel investigation, his own attorney general and what he described as a lack of focus on former presidential opponent Hillary Clinton, calling it a "disgraceful situation."
He also appeared to entertain the notion of firing Mueller. "Many people have said, 'You should fire him.' Again, they found nothing," the president said of the special counsel and his team.
"It's a total witch hunt," Trump added. He repeated the sentiment in another tweet Tuesday morning.
– CNBC's Dan Mangan and Kevin Breuninger contributed to this report.
