For the last five months, Chicago-based pediatrician Emily Lieberman has been splitting her time between treating patients and parenting two young daughters — along with trying to get assault weapons banned in the US.

It’s a lofty goal in a country that has more guns than it does people, but she’s not alone in the fight. Earlier this month, Lieberman traveled to Washington with 50 other doctors in a last-ditch attempt to get a vote on the assault weapons ban before the current legislative session ends. Over the course of two days, the group met with dozens of lawmakers on both sides of the aisle.

The doctors’ message is a simple one: Gun violence is a public-health crisis.

“We want to make sure our position is clear: Failing to pass an assault weapons ban means more patients on our operating tables and explaining to families that their loved one is never coming home,” the doctors wrote in a letter to US senators.