The nation's largest retailer, meanwhile, made news for reversing a decision -- and saying it will participate in a White House meeting.

Wal-Mart initially said scheduling conflicts would prevent its "experts" on gun control from attending. But on Wednesday it announced it will send representatives to the Thursday meeting.

The company has had "ongoing conversations with the administration, Congress, (New York) Mayor (Michael) Bloomberg's office, sportsmen groups, suppliers and others to listen and share our thoughts and experiences," company spokesman David Tovar said in a statement to CNN.

"Knowing our senior leaders could not be in Washington this week, we spoke in advance with the vice president's office to share our perspective," he said. "We underestimated the expectation to attend the meeting on Thursday in person, so we are sending an appropriate representative to participate."

Wal-Mart sells guns and ammunition.

States, cities make their own moves

Across the country, people are sharing their views on what Washington should decide. Among them are Californians who have packed town hall meetings.

Some have spoken out in support of renewing a ban on assault weapons -- high-capacity weapons that have been used in numerous mass shootings. Sen. Dianne Feinstein, a California Democrat, is pushing to reinstate a ban that expired in 2004.

But others at the town halls argue that banning those guns isn't the answer, and could even be a slippery slope toward banning all guns.

New York Gov. Andrew Cuomo, in his annual State of the State address, said Wednesday his state must enact "the toughest assault weapons ban in the nation, period."

"Gun violence has been on a rampage as we know first hand and we know painfully. We must stop the madness, my friends," he said. "It has been enough."

Bloomberg, a longtime advocate of stricter gun control, is pushing for tough steps nationwide.

In Connecticut, Gov. Dannel Malloy choked up discussing the Newtown shooting, and said "more guns are not the answer."

"Freedom is not a handgun on the hip of every teacher and security should not mean a guard posted outside every classroom," he said Wednesday in the State of the State address.

Burlington, Vermont, a city of less than 43,000 people, has already made a move of its own: passing a resolution that could lead to a ban on assault rifles and high-capacity magazines.

The city council voted 10-3 in favor of the resolution, which will now be presented in public hearings and voted on by the public before going to the state legislature.

Amid the cacophony of voices battling over the issue, two young former Marines have found themselves in a spotlight online, representing very different views.

First, Joshua Boston posted on CNN iReport an open letter to Feinstein explaining why he would not abide by an assault weapons ban. "I do not believe it is the government's right to know what I own," he wrote in the post, which went viral. "Nor do I think it prudent to tell you what I own so that it may be taken from me by a group of people who enjoy armed protection yet decry me having the same a crime."

On Tuesday, Nick DiOrio responded with his own iReport. Marines don't believe in following the law "only when it suits us," DiOrio wrote, calling Boston's letter "embarrassing because he makes Marines seem insensitive and uncaring." DiOrio said he supports an assault weapons ban.