The three days of Supreme Court hearings discussing the constitutionality of President Obama’s Affordable Care Act begin Monday, March 26.

The act, which passed in March of 2010, places new requirements on insurance companies, employers and states, as well as mandating health insurance for all citizens or pay penalties. The intention was to provide coverage to the millions of Americans without health care, according to The New York Times.

The Supreme Court’s decision, expected in June, could affect the presidential race and also stands to help define the careers of both Obama and Chief Justice John G. Roberts Jr.

The lawyers involved in the Supreme Court case have been practicing mock arguments in what are known as moot courts. The lawyer representing the 26 states challenging the constitutionality of the act, Paul D. Clement, told The New York Times that the variety of topics that will be discussed as well as the length of the arguments will challenge the lawyers.

The case has been separated into four major issues, the first being whether the act infringes on constitutional rights or not. This issue will be discussed on Tuesday, March 27. The hearings will be kicked off with arguments over whether the case should be heard or not on Monday according to The New York Times.

The case will total six hours of hearings. Clement, along with opposing counsel Solicitor General Donald B. Verrilli Jr., are scheduled to argue three times each.