He has represented companies such as TPG, Douglas Elliman Realty, Teva Pharmaceuticals, Pilgrim's Pride, Fairfax Financial Holdings, Liggett, MBIA, Woodstock 50, and Hoechst Celanese.
[10][21] After the 1993 World Trade Center bombing, Kasowitz defended the Port Authority of New York and New Jersey in a lawsuit filed by victims of the attack.
[22] He has also defended Bill O'Reilly from allegations of sexual harassment,[23] who was ultimately forced out at Fox News in April 2017.
[24] Early wins for Kasowitz included obtaining a $300 million settlement on behalf of 3,500 Alabama residents who were allegedly poisoned by seepage from a Monsanto Company plant manufacturing PCBs.
[25][26] According to a May 23, 2017, article in The Forward, Kasowitz, Benson, Torres, and Friedman has been a "go-to source" for Donald Trump for decades.
[11][29][30][31][32] In Spring 2017, Kasowitz told associates that he had been personally responsible for the abrupt dismissal of U.S. Attorney Preet Bharara on March 11, 2017, having previously warned Trump, "This guy is going to get you".
[34] According to U.S. court records, Kasowitz's clients include the Russian oligarch Oleg Deripaska, a close associate of Vladimir Putin and a business partner of Trump's former campaign manager Paul Manafort.
[39][40] In 2017, ProPublica reported that Kasowitz may be ineligible for a federal security clearance due to his alcohol abuse.
[15] In recent years, Marc and Lori Kasowitz have donated hundreds of thousands of dollars to Republican causes and to Donald Trump's presidential campaign.