Democratic presidential candidates expressed outrage Saturday that mass shootings have become chillingly common nationwide and blamed the National Rifle Association and its congressional allies after a gunman opened fire at a shopping area near the Texas-Mexico border, Associated Press writes.

“It’s not just today, it has happened several times this week. It’s happened here in Las Vegas where some lunatic killed 50 some odd people,” Vermont Sen. Bernie Sanders said as he and 18 other White House hopefuls were in Nevada to address the nation’s largest public employees union. “All over the world, people are looking at the United States and wondering what is going on? What is the mental health situation in America, where time after time, after time, after time, we’re seeing indescribable horror.”

Later Saturday night, Trump tweeted condolences. “Today’s shooting in El Paso, Texas was not only tragic, it was an act of cowardice. I know that I stand with everyone in this Country to condemn today’s hateful act. There are no reasons or excuses that will ever justify killing innocent people. Melania and I send our heartfelt thoughts and prayers to the great people of Texas.”

Read more: Deadliest days in history of Texas - Brutal act left 20 dead in El Paso

The shooting was personal for former Rep. Beto O’Rourke, an El Paso native who represented the city in Congress for six years. He suspended campaigning to fly home and “be with my family and be with my hometown.”

O’Rourke said the U.S. may require direct action, urgency and in some cases nonviolent civil disobedience, to make real change.

“I believe in this country. I believe, at the end of the day, we’re going to be able to get this done,” he said, “but it’s going to be because of those people who force it to get done.”

Former Vice President Joe Biden said he tried to call O’Rourke and told reporters, “Enough is enough.”

“This is a sickness,” Biden said. “This is beyond anything that we should be tolerating.” He added: “We can beat the NRA. We can beat the gun manufacturers.”