Colorado STEM school shooting: What the 2020 candidates are saying

Many 2020 presidential hopefuls have reacted to the shooting at STEM School Highlands Ranch in suburban Denver Tuesday, with several stressing their pledges to change gun laws.

Details: The White House called it a "hateful and horrible" act of violence and said President Trump was monitoring the situation. Here's how 2020 presidential candidates reacted.

What the presidential candidates are saying:

• Sen. Elizabeth Warren: She tweeted, "Heartsick for the victims, their loved ones, and the Highlands Ranch community. How many more of our children’s schools must be torn apart by gun violence until Congress does something? We need gun reform. Now."
• Sen. Cory Booker: He tweeted, "My heart aches. Another day, another school shooting. Every hour we wait more people are murdered—we have to pass comprehensive gun safety reform."
• Southbend, Indiana, Mayor Pete Buttigieg: He tweeted, "We have to solve the mass shooting epidemic. We — especially our students — should all feel safe in our communities. I’m praying for the students and families from STEM School Highlands Rach, and will not rest until we deliver common-sense gun reform."
• Sen. Kirsten Gillibrand: She tweeted, "Another school shooting. Another life cut far too short. Another family and community changed. Forever. How many more will it take? I’m holding Highlands Ranch in my heart tonight. This can’t go on."
• Sen Kamala Harris: She tweeted, "How many more children have to watch their classmates get shot before Congress and the White House act?"
• Former Texas congressman Beto O'Rourke: He tweeted a video post of an interview on gun violence alongside his comments, "Yesterday, a 14-year-old told me she was afraid that she would be shot in her classroom. Today, students in Highlands Ranch were shot in theirs. We are not doing enough to protect the lives in our lives. We must take action now to stop gun violence in our communities."
• Sen. Amy Klobuchar: She tweeted, "My heart goes out to the victims & their families at the STEM School Highlands Ranch, just eight miles away from Columbine High School. This has to stop. We must pass federal laws to end gun violence."
• Rep. Eric Swalwell: He tweeted: "One thing we can all agree on: This should not be a child's reality. #EnoughIsEnough #STEMShooting"
• Rep. Seth Moulton: he tweeted, "This is the only country in the world where this happens regularly. Everyone else has figured it out — there should be no reason we haven’t."
• Washington Gov. Jay Inslee: He tweeted, "My heart goes out to the Highlands Ranch community and the families of those injured. Every person in America should feel safe at school, the movies, nightclubs, their place of worship — everywhere. Aggressive gun safety reform is the only answer."
• Former HUD Secretary Julián Castro: He tweeted, "We’ve lost another young person today, and seven more injured. This is not the nation we set out to become. We are losing our children to gun violence. They are our future, and we must do better to protect them."
• Sen. Michael Bennet: He tweeted, "Heartbroken for this student’s family, loved ones, and classmates, and for everyone affected by today’s tragedy. This sickening reality has become too normal for our children. They deserve better. We have to do better. "

• Venture for America founder Andrew Yang: He tweeted, "Every shooting hurts. Let’s do something about it while it still hurts. The danger is we become numb and it becomes commonplace. We can do much more - we owe it to the next generation to rise to the challenge of school shootings via both improved mental health and gun safety."
• Former Gov. John Hickenlooper: He tweeted, "My heart is with the parents, students, and faculty of @stemschoolHR , and the first responders who rushed to their aid. This is every parent's nightmare, and it's becoming every child's nightmare as well. We can't just accept this. We have to end this epidemic of gun violence."
• Miramar, Florida, Mayor Wayne Messam: He tweeted: "Until this nation decides to have the political will to change the course of inaction, more tragedies are certain. I believe America can act and I believe these tragedies can end. I have the political will to fight for this. #ChangeCantWait"
• Spiritual leader, author and activist Marianne Williamson: She tweeted, "Another school shooting in Denver. Once again our NRA-owned senators & congressmen will offer thoughts & prayers & yet do nothing. I pray for the victims & for those who love them. And I pray for forgiveness for a country that puts gun sales before the safety of our own children."