Rivkin gained national recognition as a representative of conservative viewpoints, frequently testifying before congressional committees, and appearing as an analyst and commentator on a variety of television and radio stations.

In 2010, Rivkin took on his highest-profile case to date when he agreed to represent a multi-state lawsuit, consisting of 26 state attorneys general against health care reform legislation signed into law by President Barack Obama in March.

[8] The lawsuit, filed in the Federal Court's Northern District of Florida, argued the legislation was an "illegal expansion of Congress' regulation of interstate commerce and unfairly penalizes uninsured people who refuse to buy into the program".

[9] Rivkin represented former Defense Secretary Donald Rumsfeld in a lawsuit by José Padilla, who said he was tortured while in custody; he also helped "craft legal strategy for the State of Texas as it fights federal proposals on health care and environmental regulation".

While at OPD, he worked on a wide variety of constitutional, domestic, and international issues, including judicial selection, legal policy, immigration and asylum matters, and intelligence oversight.

[15][16] He also handled the development and implementation of President Bush's de-regulatory initiatives, carried out from 1991 to 1992, which focused on a review of existing federal structures in an attempt to make them more cost-effective.

He also helped in the passing of the Clean Air Act (1990) and FERC Order 636, known as the Restructuring Rule, designed to allow more efficient use of the interstate natural gas transmission system by fundamentally changing the way pipeline companies conduct business.

[19] Rivkin became lead outside counsel in the lawsuit filed by multiple state attorneys general seeking to nullify the Patient Protection and Affordable Care Act.

In a Wall Street Journal opinion article, Rivkin called the law "in its design, the most profoundly unconstitutional statute in American history; in its execution, one of the most incompetent ones".

Rivkin appeared as a guest analyst on TV and radio programs, including CNN, MSNBC, NBC, ABC, CBS, FOX News, NPR, PBS, The Laura Ingraham Show, Al Jazeera, the BBC, and others.

[42] Rivkin represented Colombian businessman Alex Saab, detained in 2020 during a fuel stop in Cape Verde and extradited to the United States, where he was charged with money laundering of hundreds of millions of US dollars.