"So there are two votes, and because of the weekend and what I saw happening in Connecticut , it caused me in a very deeply and emotional way, as I guess it did everyone, to seriously consider voting for those," he said. "And under normal circumstances, I'd be on the other side."
Casey's introspection isn't a unique tale among normally pro-gun Democrats. In a high-profile acknowledgment, Sen. Joe Manchin of West Virginia said that, at least for now, he is open to reconsidering measures he once opposed. Rep. John Yarmuth of Kentucky has supported gun-control measures in the past, but in an impassioned speech made it clear he would no longer stay silent about the need for such legislation.
"We woke up Saturday morning to a different nation than we were 24 hours earlier," said Rep. Nick Rahall of West Virginia, another pro-gun Democrat who has said he is willing to consider banning high-capacity clips.
For now, measures to limit guns might be gaining popularity after the Sandy Hook shooting. A plurality of 49 percent of Americans say that it's more important to control gun ownership than to protect the rights of gun owners, according to a poll released on Dec. 20 by the Pew Research Center. Forty-two percent say the opposite. It's the first time since President Obama took office that Pew has found that more American prioritize gun control over protecting gun-ownership rights.
It's not just congressmen who have reexamined their opinions, according to Rep. Tim Holden of Pennsylvania, a normally pro-gun Democrat whose campaign received a contribution from the NRA's political arm during the 2012 cycle. "I was just talking to my brother a couple of hours ago, and he's a much more avid hunter than I am; and he was, like, something's gotta happen here," he said.
Holden, who lost his primary to a more liberal Democrat, said he would likely support reinstating a nationwide assault-weapons ban if he were still in office next year. Holden, in fact, voted for an assault-weapons ban in 1994, a vote many Democrats continue to believe helped fuel the GOP's takeover of the House during that year's midterm elections.
Holden said he took a "political beating" for the vote but nonetheless survived. Gun laws are a difficult issue for many Democrats, especially those who represent culturally conservative districts. Out of political necessity, they have to distinguish themselves from liberals such as House Minority Leader Nancy Pelosi of California. And few issues offer a greater opportunity to do so than opposing gun control, an issue that resonates viscerally among most voters.
Rep. Mike Thompson, D-Calif., is familiar with the dilemma. The Vietnam War veteran and avid hunter, who supports reinstating the assault-weapons ban, was just named head of a House Democrats' task force on gun violence. In an interview, he made clear the importance of assuring fellow citizens that the government doesn't plan to take away their guns.