The Supreme Court will reconvene Tuesday to hear oral arguments in several key cases, including the legal challenge to President Trump’s roll back of the Deferred Action for Childhood Arrivals program.

Others are a compelled speech case involving crisis pregnancy centers in California, and a partisan gerrymandering case involving the Maryland congressional map.

Here are the four big Supreme Court cases to watch:

Janus v. AFSCME

The justices will hear oral arguments in a case out of Illinois that questions whether the 1977 case Abood v. Detroit Board of Education should be overturned. In Abood, the court ruled that nonunion public employees still have to pay agency fees, which fund collective bargaining negotiations.

The justices heard a similar case, Friedrichs v. CTA, in 2016, but deadlocked at 4-4 after Justice Antonin Scalia’s death.

A decision in favor of Janus could deal a significant blow for unions, as the case would effectively make union dues optional for public-sector employees.

The court will hear oral arguments in the case Feb. 26.

U.S. v. Microsoft Corporation

The Supreme Court will meet this month to consider whether a private company, when served with a warrant, is required to turn over emails to the federal government, even when the data is stored outside of the U.S.

The case dates back to 2013, when the federal government served Microsoft with a search and seizure warrant for the data related to an MSN account. The customer’s account information was stored on a server in the U.S., which Microsoft turned over, but emails were stored in a data center the company has in Dublin, Ireland.

Microsoft attempted to vacate the order, but a magistrate judge denied their motion, holding the relevant place was where the government would review the data, in the U.S., not where it was stored in Ireland.

A panel of judges on the 2 nd U.S. Circuit Court of Appeals sided with Microsoft.

The justices will hear oral arguments in the case Feb. 27.

National Institute of Family and Life Advocates v. Becerra

In the case NIFLA v. Becerra, the justices will consider whether a California law that requires licensed facilities to inform patients about access to family planning services, including abortions, violates First Amendment free speech protections.

Called the Reproductive FACT Act, the law regulates a “licensed covered facility,” as well as unlicensed pregnancy centers that don’t perform medical services.

Licensed centers are required to tell patients that “California has public programs that provide immediate free or low-cost access to comprehensive family planning services (including all FDA-approved methods of contraception), prenatal care, and abortion for eligible women.”

Unlicensed centers have to include disclaimers on printed and digital ads stating they’re not a licensed medical center.

Pro-life crisis pregnancy centers challenged the law, saying it violated their free speech and free exercise rights and arguing the disclaimer “drowns out the centers’ pro-life messages and discourages them from speaking through advertisements because California’s voluminous required statements make ads cost prohibitive.”

The case is the third compelled speech case, alongside Masterpiece Cakeshop v. Colorado Civil Rights Commission, and Janus v. AFSCME, the justices are hearing this term.

Oral arguments are March 20.

Benisek v. Lamone

Rounding out their March calendar for oral arguments, the justices will hear a Maryland partisan gerrymandering case.

The case challenges the constitutionality of a Maryland congressional district redrawn by the state's Democratic leaders after the 2010 census.

The congressional district, Maryland’s 6 th, had been represented by former Rep. Roscoe Bartlett, R-Md., for 20 years. But after the district lines were redrawn, Rep. John Delaney, D-Md., won the seat.

Republican voters who filed the case argued Democratic leaders infringed upon their First Amendment rights in redrawing the district to ensure a Democrat would win the seat.

Former Maryland Gov. Martin O’Malley admitted in a deposition last year the state’s map was drawn with the “intent to create … a district where the people would be more likely to elect a Democrat than a Republican.”

The case out of Maryland is the second the court will hear involving partisan gerrymandering this term.

In October, the justices heard arguments in the case Gill v. Whitford, which involves Wisconsin’s voting map.

Oral arguments are scheduled for March 28.