President Obama has arrived in Cuba for a historic three-day visit, becoming the first sitting U.S. president to visit the island in 88 years. Obama is scheduled to meet Cuban President Raúl Castro this morning at the Palace of the Revolution in Havana. A state dinner for Obama will be held tonight. On Tuesday, Obama will address the Cuban people. He is also scheduled to meet with Cuban dissidents. We’ll have more on Obama’s historic trip after headlines.

In Arizona, demonstrators shut down a highway leading to a rally for Republican presidential candidate Donald Trump outside Phoenix Saturday, delaying the rally ahead of Tuesday’s key primaries. Three people were arrested, including Jacinta Gonzalez, a leading immigrant advocate who had locked her neck to a van’s window as part of the roadblock. Jacinta González said she was then transferred to immigration custody—despite being a U.S. citizen.

Jacinta González: “Yesterday, when we were arrested, I know that the two colleagues I was arrested with were released, but because my last name is González, I was immediately questioned by ICE and placed on a detainer. After they were let go and were able to go home, I was transferred to immigration custody. This just proves that the hatred and the profiling that Trump says and tries to promote is the same that exists within this administration.”

At a Trump rally in Tucson, a Trump supporter was caught on video sucker-punching an anti-Trump protester as he was being led away. Tony Pettway was arrested for misdemeanor assault and released. The protester, Bryan Sanders, was kicked out of the rally after chanting “liar” and holding a sign that read “Trump is bad for America.”

Meanwhile, another video from the rally showed Trump campaign manager Corey Lewandowski appearing to grab a protester by his collar. The footage shows Lewandowski, in a blazer, grabbing the man at the same time as a member of Trump’s private security team. The protester is yanked backwards. Speaking to George Stephanopoulos on ABC, Trump refused to condemn the violence at his rallies, saying “professional agitators” bore much of the blame. He also praised Lewandowski’s “spirit.”

Donald Trump: “Well, you know what? Because the security at the arena, the police were a little bit lax, and he had signs—they had signs up in that area that were horrendous, that I cannot say what they said on the sign, but the ultimate word. And it was all over the camera. And frankly, the television cameras can’t take it, and they can’t do anything about it. And I will give him credit, spirit. Now, he didn’t touch. He wasn’t pulling that man. That was somebody else.”

George Stephanopoulos: “Well, the video does show that he touched him. Your private security pulled him, but it does show he grabbed the collar.”

Donald Trump: “Well, that was somebody else pulling him. I mean, I—I give him credit for having spirit. He wanted them to take down those horrible, profanity-laced signs.”

Trump campaign manager Corey Lewandowski has also been accused of grabbing the arm of a Breitbart reporter Michelle Fields, leaving her bruised.

In New York City, as many as 2,000 people marched against Donald Trump, chanting “Racist, sexist, anti-gay, Donald Trump, go away.” They marched from Trump International Hotel and Tower in Columbus Circle to Trump Tower on Fifth Avenue. Three people were arrested amid a heavy New York City police presence at Saturday’s rally. Click here for more on the rally.

Vermont Senator Bernie Sanders will skip the annual conference of the American Israel Public Affairs Committee, the powerful pro-Israel lobbying group. Sanders is the only candidate from either the Republican or Democratic Party not to attend the conference. His Democratic rival, Hillary Clinton, and Republicans Donald Trump, Ted Cruz and John Kasich are all slated to speak there. Sanders said his campaigning in Western states ahead of voting in Arizona, Idaho and Utah Tuesday would not allow him to make the trip to Washington, D.C. His campaign said AIPAC rejected his offer to address the conference by video link, even though Republicans Mitt Romney and Newt Gingrich did so in 2012.

A U.S. marine has been killed in northern Iraq. The Pentagon said Staff Sgt. Louis Cardin was killed Saturday by enemy rocket fire near Makhmur. He was 27. His death appears to have revealed the existence of a new U.S. fire base in Iraq where CNN reports hundreds of marines have been living in tents. Cardin is the second U.S. servicemember killed since the U.S. campaign against ISIL began in 2014.

In Brussels, Belgium, Salah Abdeslam, a suspect in the Paris attacks that killed 130 people, was arrested in a raid Friday. Authorities had searched for Abdeslam since the November attacks. Belgian authorities say he was plotting more attacks in Brussels.

In Istanbul, Turkey, a suicide bomber killed four people in a busy tourist area Saturday. Turkish officials said the bomber was a Turkish citizen who belonged to ISIL. The attack killed an Iranian and three Israelis, two of whom also had U.S. citizenship.

Hundreds of refugees have arrived on the Greek islands despite a new deal between Turkey and the European Union aimed at reducing the flow. Two Syrian refugees died over the weekend attempting the crossing, while two little girls were found drowned. Under the accord, all people now arriving on the islands face a return to Turkey. For every Syrian refugee sent back to Turkey from Greece, the EU has vowed to resettle one Syrian from the Turkish refugee camps.

In Brazil, demonstrators took to the streets nationwide Friday to defend the government of President Dilma Rousseff against what they say are undemocratic attempts by the right-wing opposition to oust her from power. Last week, a judge suspended Rousseff’s appointment of former President Luiz Inácio Lula da Silva to a Cabinet post. Rousseff says Lula will help strengthen her government, but critics see his appointment as a bid to protect him from what Lula says are politically motivated charges of money laundering. The judge who blocked Lula’s appointment had recently posted photos of himself on social media marching in an anti-government protest. Brazil faces a dire financial crisis and a corruption scandal that spans political sides.

In Mexico, community activist Nestora Salgado has been freed after two-and-a-half years of what a United Nations panel deemed an illegal detention. Salgado, a dual U.S.-Mexican citizen, organized a community self-defense group in her hometown in Guerrero state, where the line between drug cartels and local officials is often blurred. Salgado walked free Friday after a judge determined that kidnapping and other charges lodged against her by local officials were baseless. Speaking at a news conference, she described her imprisonment.

Nestora Salgado: “I felt that I was buried alive in a drawer. I was out of touch for 20 months, in isolation for a crime that I did not commit. They didn’t even let me coexist with the other prisoners. I only saw them when I went to court. They treated me in the most brutal way that they could. It’s difficult to struggle against the government when they are out to get you, but it’s even worse that they did this when all I wanted was to defend my community.”

Here in New York, the father of one of the 43 students missing in Mexico for 18 months ran the New York City Half Marathon Sunday in honor of his son. The students disappeared from Guerrero—Nestora Salgado’s home state—after an attack by local police. Surrounded by supporters in Times Square, Antonio Tizapa called for the United States to suspend billions in U.S. aid for the drug war in Mexico.

Antonio Tizapa: “We are asking for a halt to the Mérida Initiative. That is the message that I want to give to people in the United States, to pressure the government so they stop helping the Mexican government, because with these weapons, they are practically killing us.”

Click here to see our interview with Antonio Tizapa.

And in Western Massachusetts, a builder has placed a 10-by-15-foot replica of author and naturalist Henry David Thoreau’s cabin in the path of a proposed gas pipeline. Residents oppose the pipeline planned by energy firm Kinder Morgan, saying it threatens the local environment.