William Morgan Cassidy (born September 28, 1957) is an American physician and politician serving as the senior United States senator from Louisiana, a seat he has held since 2015.

[19] In 2010, Cassidy's alma mater, Louisiana State University, selected him for honoris causa membership in Omicron Delta Kappa, the National Leadership Honor Society.

According to Cassidy, he switched parties after the extinction of conservative Democrats and because of his frustration with the bureaucracy and inefficiency of the public hospital system.

In his first bid for public office, he defeated veteran State Representative and fellow Republican William Daniel, and Libertarian candidate S.B.

[24] On November 4, 2008, Cassidy was elected to serve Louisiana's 6th district in the U.S. House of Representatives, defeating incumbent Democratic Congressman Don Cazayoux with 48% of the vote.

In the 2010 midterm elections, Cassidy easily won a second term, defeating Democrat Merritt E. McDonald of Baton Rouge with 66% of the vote.

[26] In the 2012 election, Cassidy was reelected again defeating Rufus Holt Craig, Jr., a Libertarian, and Richard Torregano, an Independent.

[34] In 2013, due to the American Medical Association's decision to officially recognize obesity as a disease, Senators and Representatives, including Cassidy, helped introduce legislation to lower health care costs and prevent chronic diseases by addressing America's growing obesity crisis.

Cassidy said the Treat and Reduce Obesity Act could help empower physicians to use all methods and means to fight the condition.

3522; 113th Congress), sponsored by Cassidy, enabling Americans to keep health insurance policies that do not meet all of the Affordable Care Act's requirements.

[41] In March 2017, Cassidy sent a letter to one of his constituents that falsely asserted that Obamacare "allows a presidentially handpicked 'Health Choices Commissioner' to determine what coverage and treatments are available to you.

4899; 113th Congress), a bill to revise existing laws regarding the development of oil and gas resources on the Outer Continental Shelf.

[53] He said that any legislation that he would support must meet the "Jimmy Kimmel test", namely: "Would a child born with congenital heart disease be able to get everything he or she would need in that first year of life?

"[54] Kimmel had earlier chastised Republicans for voting to repeal the Affordable Care Act and replace it with legislation that would not ensure protection for children such as his newborn, who was born with a heart defect that required immediate surgery.

[54] Kimmel condemned Cassidy, calling him a liar,[54] listed the health organizations that opposed Graham–Cassidy, and urged his viewers to contact their congressional representatives about the legislation.

[62] On May 27, 2021, along with five other Republicans and all Democrats, Cassidy voted to establish a bipartisan commission to investigate the January 6 storming of the U.S. Capitol.

[9] In February 2023, Cassidy, and Sheldon Whitehouse introduced the Reinvesting in Shoreline Economies and Ecosystems Act, which aims to share federal offshore wind power revenue with states for coastal protection and restoration work.

[66] Cassidy said he struggled in deciding whether to vote to confirm Kennedy because of his ethics as a doctor ("dedicating my life to saving lives").

[2][3][4][5] In July 2019, Cassidy was one of eight senators to introduce the Agricultural Trucking Relief Act, a bill that would alter the definition of an agricultural commodity to include both horticultural and aquacultural products and promote greater consistency in regulation by federal and state agencies as part of an attempt to ease regulatory burdens on trucking and the agri-community.

[69] In July 2019 Cassidy was one of 16 Republican senators to send Acting Office of Management and Budget (OMB) Director Russell Vought, Acting White House Chief of Staff Mick Mulvaney, and Treasury Secretary Steven Mnuchin a letter encouraging them to work with them to prevent a continuing resolution "for FY 2020 that would delay the implementation of the President’s National Defense Strategy (NDS) and increase costs" and arguing that the yearlong continuing resolution administration officials favored would render the Defense Department "incapable of increasing readiness, recapitalizing our force, or rationalizing funding to align with the National Defense Strategy (NDS).

"[70] In October 2023, Cassidy visited China as part of a bipartisan congressional delegation led by Senate Majority Leader Chuck Schumer and met with Chinese President Xi Jinping.

The delegation also met Foreign Minister Wang Yi, National People's Congress Standing Committee Chairman Zhao Leji, and Shanghai Communist Party Secretary Chen Jining.

[71] In January 2024, Cassidy voted against a resolution proposed by Senator Bernie Sanders to apply the human rights provisions of the Foreign Assistance Act to U.S. aid to Israel's military.

[74] In May 2022, after the Robb Elementary School shooting, Cassidy reaffirmed his opposition to banning any kind of guns, including assault rifles such as the AR-15.

[76] Cassidy later became one of ten Republican senators to support a bipartisan agreement on gun control, which included a red flag provision, a support for state crisis intervention orders, funding for school safety resources, stronger background checks for buyers under the age of 21, and penalties for straw purchases.

[83] He supported the 2022 overturning of Roe v. Wade, calling it a decision that "recognizes that an unborn child has a right to life.