Protesters in front of the Supreme Court [AFP Yonhap News]

U.S. President Donald Trump attended the Federal Supreme Court in Washington D.C. on the 1st (local time), where oral arguments were held on his "executive order to ban birthright citizenship."

President Trump attended the oral arguments taking place at the Supreme Court starting at 10 a.m. today. The attendance of a sitting U.S. president at the Supreme Court is unprecedented.

Previously, President Trump announced in November last year that he would participate in Supreme Court arguments in a lawsuit related to the International Emergency Economic Powers Act (IEEPA), which served as the basis for imposing reciprocal tariffs, but withdrew at the last minute.

In that lawsuit, the Supreme Court ruled 6-3 in February that President Trump's imposition of reciprocal tariffs and tariffs on fentanyl based on IEEPA was illegal.

Trump's decision to break with tradition and attend the Supreme Court today appears to be driven by concerns of political damage if he loses this lawsuit as well.

Birthright citizenship is a right stipulated in the U.S. Constitution, which states, "All persons born or naturalized in the United States, and subject to its jurisdiction, are citizens of the United States and of the State wherein they reside."

However, President Trump issued an executive order immediately after taking office in January of last year, prohibiting birthright citizenship for children born to parents who are in the U.S. illegally or who do not have permanent residency.

President Trump has argued that the original intent of birthright citizenship was to grant citizenship to slaves and their children after the Civil War, not for wealthy Chinese individuals giving birth in the U.S. or for illegal immigrants in the U.S.

This reversed established policies and legal interpretations, and it drew backlash because it could strip the nationality of hundreds of thousands to millions of children born to immigrant parents.

Ultimately, 22 states, led by Democratic governors, and Washington D.C. filed lawsuits, claiming the executive order was unconstitutional, and lower courts ruled in favor of the plaintiffs.

If the birthright citizenship ban executive order is also ruled unconstitutional, following the illegal tariff ruling, it would be a series of blows for President Trump, leading to the interpretation that he intends to pressure the justices by attending the Supreme Court in person.

The ban on birthright citizenship, along with President Trump's policy of deporting illegal immigrants and his push for a bill requiring voter ID at the polls (known as the 'SAVE' Act), is also seen as an attempt to diminish the vote-getting power of Democratic candidates in the midterm elections.

However, President Trump did not speak directly in court. Deputy Assistant Attorney General John Sauer, representing the executive branch, answered the justices' questions.

Deputy Assistant Attorney General Sauer argued that citizenship should be granted not merely based on being born in the United States, but also by considering the legality of the parents' stay and their loyalty to the American political system.

The justices questioned the government's logic, centering on the 1898 "Wong Kim Ark" precedent, which recognized the citizenship of a child born in San Francisco to Chinese parents.

In this context, they also asked about the government's position on the 1952 Immigration and Nationality Act, which states that "all persons born in the United States and subject to its jurisdiction are citizens." It was also pointed out that recognizing the authority of the U.S. political system and its laws and institutions would be sufficient.

The Supreme Court ruling is expected this summer. Current projections from U.S. media largely suggest that President Trump does not have a high probability of winning.

In front of the Supreme Court, where the oral arguments were held today, protesters, estimated to include immigrant families from Korea, gathered to urge a ruling against President Trump's executive order.

Vehicle of President Trump arriving at the Supreme Court [AFP Yonhap News]