A CNN poll released this week shows striking evidence of a shift in American attitudes toward mass shootings: Nearly two-thirds of adults now believe that mass shootings can be prevented, the first time since Columbine that a majority of Americans have felt that way.

The survey suggests the Parkland, Fla., shooting is changing the public attitudes about gun violence in a way that other recent killings haven't.

As recently as the summer of 2015, when nine black parishioners were shot to death by a white supremacist in a Charleston church, less than 40 percent of Americans said that government or society could do anything to stop the shootings.

Four months ago, when 58 people were killed and hundreds more injured in a shooting in Las Vegas, a plurality of respondents told pollsters that government and society were essentially powerless to stop these incidents.

Today, however, 64 percent of Americans say that “government and society can take action that will be effective in preventing shootings like the one in Parkland, Florida from happening again.” Just 32 percent say shootings like Parkland “will happen again regardless of what action is taken by government and society.”

The question has referenced different shootings each time it's been asked, so some of the variation in responses to it likely reflects the differences between those shootings: venue, victims, shooters and other individual circumstances.

But the numbers nonetheless reflect the contours of a political routine with which we've all become familiar: a national tragedy, followed by outrage, prayer and calls for action. Ultimately, however, federal firearm policy remains unchanged, an outcome driven in large part by congressional Republicans' vehement opposition to substantive regulations on gun ownership. In the past, some red-state Democratic senators, such as North Dakota's Heidi Heitkamp and West Virginia's Joe Manchin III, have also been instrumental in voting down new gun control policies.

The recent shift in the public's attitudes, however, is primarily concentrated among Republicans. In October, after the Las Vegas shooting, 24 percent of Republicans said that “government and society can take action that will be effective in preventing shootings.”

This month, after the school shooting in Parkland, in which 17 students and educators were killed and 14 more were injured, Republican belief that government and society can stop mass shootings jumped by nearly 30 percentage points, to 52 percent.

The CNN poll shows strong Republican support for at least two specific gun control proposals. Ninety percent said they support a prohibition on gun purchases by convicted felons or people with certain mental health issues. The question, however, didn't define what mental health issues would qualify for this policy.

More than 60 percent of Republicans also support raising the age limit to 21 for all gun purchases, including rifles. Currently, federal law sets an age limit of 21 for handgun purchases from licensed dealers and a limit of 18 for rifles. Because of that, the Florida school shooter had been able to legally obtain the military-style rifle used in the shooting despite being only 19.

Nearly half of Republicans favor a ban on magazines capable of holding more than 10 rounds. More than one-third support a ban on all semiautomatic rifles, a measure that would be more restrictive than the 1994 assault weapons ban, which outlawed only certain types of semiautomatic rifles. A limit on the number of guns individuals could own is even less popular among GOP voters.

The CNN survey also traces how public response to mass shootings has become more polarized over time. From 2000 through at least 2005, Democrats and Republicans were separated by fewer than 10 percentage points on the question of whether government and society can take steps to stop mass shootings.

But after the shooting of U.S. Rep. Gabby Giffords and 18 other individuals at a 2011 political event, that began to change. The gap between Democrats and Republicans grew to larger than 20 points after that shooting, surpassed 30 points after the Sandy Hook school shooting, and hit a peak of 44 points after the Las Vegas shooting in October.

After the Parkland shooting, the gap has narrowed to 27 points, still a formidable divide. Whether the shared belief that mass shootings can be stopped represents a moment of unity or a more durable trend will likely depend, on large part, on whether Congress is able to pass any meaningful legislation to address the violence.