President Donald Trump's personal lawyer, John Dowd, revealed Monday a potential legal defense in the ongoing Russia probe, claiming that a president cannot obstruct justice. "The president cannot obstruct justice because he is the chief law enforcement officer under (the Constitution's Article II) and has every right to express his view of any case," Dowd told NBC News Monday. Dowd added that the president's weekend tweet — which many have argued strengthened a potential obstruction of justice case for special counsel Robert Mueller — "did not admit obstruction." "That is an ignorant and arrogant assertion," Dowd said. His comments were first reported by Axios and came two days after Trump tweeted, "I had to fire General Flynn because he lied to the Vice President and the FBI." "He has pled guilty to those lies. It is a shame because his actions during the transition were lawful. There was nothing to hide!" Trump wrote in his Saturday tweet — his first public comments about his former national security adviser after Michael Flynn pleaded guilty to lying to the FBI about speaking with Russian officials. The tweet caused an uproar in Washington because it implied Trump knew Flynn had committed a felony — lying to the FBI — when he told then-FBI director James Comey to go easy on Flynn the day after the firing. Interfering in the FBI's investigation could be construed as obstructing justice, potentially creating legal jeopardy for Trump, some experts argued. Attorney John Dowd, President Donald Trump's personal lawyer. Brendan McDermid / Reuters file But within a few hours of the Saturday post, Dowd stepped in to say that he wrote the tweet, not the president. Meanwhile, several lawmakers and legal experts immediately weighed in Monday morning to express their disagreement with Dowd's position that the president cannot obstruct justice. "I hope my Republican colleagues in the U.S. Senate will take the lead on this issue and also on obstruction of justice. There is a credible case of obstruction of justice against Donald Trump," Sen. Richard Blumenthal, D-Conn., said on MSNBC’s "Morning Joe." "If you take the president's own statement, his tweet that he knew