On Tuesday, the Supreme Court ruled 5-4, along ideological lines, that the family of a Mexican teenager who was killed across the southern border by a U.S. border agent cannot sue for damages.

Why it matters: The court’s decision avoids inviting more lawsuits from foreign nationals against U.S. law enforcement. The court noted in its opinion that “a cross-border shooting claim has foreign relations and national security implications.”

Effective Monday, the U.S. will begin blocking more foreigners from obtaining green cards and some visas based on the Trump administration's guesses about what kind of people they'll become and whether they may ever burden taxpayers.

Why it matters: The long-expected "public charge" rule effectively creates a wealth and health test, which could keep hundreds of thousands of people from making the U.S. their legal home.

U.S. Supreme Court Justice Sonia Sotomayor issued a dissenting opinion on Friday against the court's 5-4 vote to allow the Trump administration to penalize immigrants likely to rely on public programs like food stamps and Medicaid.

The big picture: The Trump administration has consistently tried to get controversial cases in front of the Supreme Court as quickly as possible, routinely asking the high court to step in before appeals courts have a chance to rule, Axios' Sam Baker reports. Sotomayor is apparently expressing her dissent at this new arrangement as well as the ruling itself.

Greyhound said it will stop allowing Border Patrol agents without a warrant to board its buses to conduct routine immigration checks, AP reports.

What they're saying: The company said it'll notify the Department of Homeland Security that it does not consent to unwarranted searches on its buses or in areas of terminals that are not open to the public.

Today's Nevada caucus will foreshadow the future of American politics well beyond 2020.

Why it matters: The U.S. is in the midst of a demographic transformation, and the country's future looks a lot like Nevada's present. Today's results, in addition to shaping the 2020 race, will help tell us where politics is headed in a rapidly changing country.

Immigration is projected to drive most population growth in the United States by 2030, and cutting immigration levels will do little to alter the nation's coming racial and ethnic transformation, according to a new Census Bureau study on population projections.

Why it matters: A growing population will be essential to the U.S.'s long-term economic growth.

Specially trained border officials are being deployed to a handful of sanctuary cities to help carry out an immigrant arrest operation to begin this weekend alongside Immigration and Customs Enforcement (ICE) agents, the New York Times reports.

Why it matters: The administration has made several efforts over the past few weeks to crack down on states and cities that choose not to cooperate with federal immigration enforcement agencies.

The number of attempted illegal crossings at the U.S.-Mexico border fell for the eighth straight month in January to 36,679, Customs and Border Protection Acting Commissioner Mark Morgan said in a press briefing on Tuesday.

Why it matters: Last year’s border crisis largely consisted of Central American families and children attempting to reach the U.S., but over the last few months, the Trump administration has begun implementing asylum agreements with those nations. That has allowed immigration officials to deport asylum seekers to Central American countries that are not their home.

The Department of Justice on Monday announced a slew of lawsuits targeting New Jersey, California and King County, Washington, over laws and policies that the agency claims make it harder to enforce federal immigration law.

Why it matters: The administration has long railed against "sanctuary cities" and has been rolling out retaliatory actions against states, counties and cities that refuse to cooperate with federal immigration law enforcement.