WASHINGTON » A visibly frustrated President Barack Obama said Thursday that thoughts and prayers are no longer enough as Americans respond to another deadly school shooting, and he challenged voters wanting to deal with the problem to vote for elected officials who will do something.

Obama addressed the nation from the White House after 13 people were killed by a 20-year-old gunman at Umpqua Community College in southwestern Oregon. As he noted, he’s done this before. Mass shootings have become embedded in the arc of Obama’s presidency. He’s traveled to Aurora, Colorado; Tucson, Arizona; Charleston, South Carolina, and numerous other cities to mourn victims of gun violence.

Obama, with some anger in his voice, said the nation has become numb to such shootings and the response has become routine. He called for changes in the nation’s gun laws, though it’s unclear at this stage whether the changes often proposed would have prevented Thursday’s massacre.

The White House’s failed push for gun control legislation after the 2012 Newtown, Connecticut, shooting — in which 20 children and six adults were killed at an elementary school — deeply frustrated Obama. With little change in Washington’s political dynamic, he hasn’t made a concerted effort to renew the gun control effort. In responding to Thursday’s shooting, Obama asked how anyone with a straight face can make the argument that more guns will make people safer.

"I’d ask the American people to think about how they can get our government to change these laws and to save lives and to let young people grow up, and that will require a change of politics on this issue," Obama said.

Obama said there is a gun for roughly every man, woman and child in the U.S.

"I hope and pray that I don’t have to come out again during my tenure as president to offer my condolences to families in these circumstances," Obama said. "But based on my experience as president, I can’t guarantee that. And that’s terrible to say."