Will this time be any different?

As Americans try to process another horrific mass shooting, many have asked whether anything will change, given all the shootings that have come before. In one measurable way, however, the murder of innocent children at Sandy Hook Elementary School is already different.

It is driving the largest organic push for gun control in many years. In fact, by Monday afternoon, calls for gun regulation on the White House website had eclipsed every other topic over the past year, including the previous record-holder, a petition advocating that Texas secede from the Union.

In roughly three days, more than 150,000 people have signed a petition calling on the White House to back legislation limiting access to guns. That is the most support that any petition has drawn since the White House launched its “we the people” platform. The concise petition states that gun control is the “only” way to reduce “the number of people murdered in gun related deaths.” Striking a cooperative tone, it also advocates a “bipartisan discussion” to advance gun regulation constistent with the Second Amendment.

Under new rules instituted by the Obama administration, any petition submitted online that garners 25,000 supporters is entitled to an official response from the administration. Sometimes the official responses are dismissive—like the president’s announcement that he still opposes legalizing pot—but the mechanism can also advance neglected issues.

The unusually strong support for this White House petition comes as other online efforts are breaking records of their own.

Staci Sarkin, an activist in New York, wrote her own petition calling for gun control in response to the Sandy Hook shooting.

“How many more senseless and entirely PREVENTABLE shootings have to occur,” she wrote, “before we do something about Gun Control.” Sarkin used SignOn.org, an organizing hub run by MoveOn.org. When her petition began “spreading rapidly” this weekend over e-mail and Facebook, MoveOn says it decided to circulate the impassioned appeal to its e-mail list. (MoveOn has about 7 million members.)

By Monday afternoon, Sarkin’s petition had 320,000 supporters and counting. “We’re seeing a massive surge in member energy around these issues, compared to a normal moment,” says Manny Herrman of MoveOn.org. “The top [gun control] petitions have brought in over 450,000 signatures,” he told The Nation, “and 193 new petitions have been created on this issue so far—an all time record.”

Sarkin’s call, like the popular White House petition, focuses on practical steps to regulate access to guns—not ban them. She writes:

Gun Control doesn’t have to mean no guns… I’m suggesting we put tighter controls on acquiring and owning them. Gun show loopholes must be stopped. Ammunition should not be sold online. Mandatory wait periods should be enforced during which time a thorough background check, psychological and medical evaluation and character references should be completed… Training and testing should be mandatory.

While it’s easy to discount a sudden outpouring over such a terrible incident, the unusually large, spontaneous interest in these petitions could stoke a larger effort. (Some activists are also specifically targeting the NRA.) After all, in the Obama era, the protests which gained the strongest followings have focused on problems that both parties failed to address. Occupy tackled income inequality, for example, while the Tea Party initially rallied against bailouts for Wall Street.

The politics of gun control have been fecklessly frozen within the consensus of the GOP and the Democratic Party for a long time—from the anguished but largely apolitical discussions after the recent spate of shootings, to a series of concrete legislative actions favoring the gun industry. (Congress and the past two presidents have been countering gun control, from a recent 2010 law allowing loaded weapons in national parks, to the 2005 law granting gun manufacturers immunity from lawsuits regarding gun violence.) Now, once again, people are talking about political “leadership” on gun control. If we want leadership, it’s clear that it will have to start from the bottom up.

Read George Zornick’s latest on how Walmart made Adam Lanza’s AR-15 the most popular assault weapon in America.