### The Evolution of Travel Bans in the Trump Administration

During his first term, President Trump implemented a series of travel bans, each adapting to meet legal standards and address national security concerns. These bans, introduced between 2017 and 2020, affected various countries and faced considerable legal challenges.

The initial travel ban targeted citizens from Iran, Iraq, Libya, Somalia, Sudan, Syria, and Yemen, prohibiting their entry into the United States for 90 days. This controversial move was soon halted by a federal judge in the case of Washington v. Trump. In response, the administration introduced a second version, which removed Iraq from the list and exempted individuals with existing green cards or valid visas.

Despite these adjustments, two federal judges blocked key provisions of the second ban, particularly the sections that restricted travel from six of the previously listed countries. Continuing its efforts, the Trump administration then issued a third travel ban. This version included citizens from Chad, Iran, Libya, North Korea, Somalia, Syria, Venezuela, and Yemen, although Iranian nationals with valid student and exchange visitor visas were allowed entry.

The third ban encountered several legal challenges, but notably, the Supreme Court permitted it to take effect while such challenges were ongoing. Eventually, Chad was removed from the list after the country addressed the administration's security concerns. The Supreme Court later upheld the third travel ban with a 5-4 vote, affirming the president's authority over national security concerns in immigration matters.

In a continuation of its policy, the Trump administration introduced a fourth travel ban. This ban restricted immigrants from Eritrea, Kyrgyzstan, Myanmar, Nigeria, Sudan, and Tanzania, although it allowed tourists and others visiting on a temporary basis to enter the United States.

Upon taking office, President Biden acted swiftly to revoke all of President Trump's travel bans, marking a significant shift in the nation's immigration policy.