A grim President Barack Obama says the U.S. has “become numb’ to mass shootings like Thursday’s incident in Oregon, where a 20-year-old gunman killed at least 9 people at Umpqua Community College.

Speaking in the White House briefing room Thursday, Obama challenged voters wanting to deal with the problem to vote for elected officials who agree with that priority.

He has had no success through his nearly seven years in the White House in getting Congress to tighten laws involving firearms.