Sen. Joe Manchin, a conservative Democrat from West Virginia and "proud gun owner," said he's now committed to "dialogue that would bring a total change" given what happened in Newtown.
"Who would have ever thought, in America or anywhere in the world, that children would be slaughtered?" he told CNN. "It's changed me."
The debate is playing out not just in Washington, but across America.
John Licata told CNN's iReport there needs to be better vetting before people buy guns, and assault weapons should be banned -- something Sen. Dianne Feinstein, D-California, says she'll propose once the new Congress convenes in January.
CNN iReporter Jameson Riley said the shooting shows the need for more armed guards in schools. Riley, a gun owner, said recent mass shootings have made him consider getting a concealed weapon permit.
"I have a 2-year-old daughter, and she is the light of my life," he said. "And I would like to protect her."
Others said Americans shouldn't change how they live, contending that doing so is a victory for perpetrators of violence.
"Yes, I hugged my son so tight when he got home from school that day that he asked what was wrong," one CNN.com commenter wrote. "But I refuse to let evil monsters intimidate me into living my life -- or raising my son -- in fear."