In the wake of last week's mass shooting in a Florida high school, there have been heightened calls for gun control. But will the most recent massacre—in which 17 people, mostly students, died—result in substantial changes to laws restricting the ability to own and carry firearms? If the past couple of decades are any guide, the answer is no.

The era of modern mass shootings can be roughly dated to the Columbine High shooting in 1999. You might expect that event to have started a movement for more gun control, but the long-term trends show a very different correlation. Here's data from Pew on surveys that asked people whether they think the government should do more to control gun ownership or protect gun rights. The data, which begins in 1993 and runs through last April (before the Las Vegas and Sutherland Springs shootings last fall), shows a long-term increase in the percentage of Americans supporting gun rights.

CNN pollster Harry Enten writes that "past history suggests that any bump in public opinion in favor of gun control will not hold. The long-term trend is against gun control." That helps explain why Congress, even when it was fully controlled by Democrats in 2009 and 2010, didn't push new laws. He further notes that millennials and younger Americans are no exception:

That young adults aren't any more likely to be in favor of stricter gun laws than the average America is even more remarkable when you consider that young adults today are politically more liberal than young adults at the time of Columbine. In fact, mass shootings didn't make young adults more in favor of gun control than the average American. It may have had the opposite effect.

Such a read is consistent with the notion, which I wrote about yesterday, that younger Americans have positions on issues that cluster very differently than those of who are older. This isn't suprising in any way, but it's worth paying attention to, especially for those of us interested in shifting the direction of U.S. policy. The old alliances, both within movements and among them, are less and less relevant every day and, given the increasing number of individuals who say they are independent and unaffiliated, the future will belong to those who can define a broad-based set of principles for people to rally around.

In the Democratic Party and the left-liberal side of the political spectrum more generally, the glue that held progressives and centrists is breaking down (that's the subtext of the Sanders insurgency in 2016 and the rise of identity politics at the cost of class-based politics). You end up with figures such as Hillary Clinton and Joe Biden, who are drug warriors and military interventionists in ways that alienate harder-left elements. At the same time, they are not interventionist enough in the economy to inspire confidence in Bernie fans. Bernie himself isn't quite the right face for a Democratic party or left that wants to talk more about race and gender than class. In the GOP and the broad right, libertarians started peeling away from conservatives immediately after the collapse of the Soviet Union; the insistence on foreign-policy adventurism on the part of neoconservatives made that gap still wider, especially given the neocons' general unseriousness about economic policy. The reactionary lifestyle politics doesn't play well with libertarians either and fewer and fewer people in general. Add populism to the mix and the coalition that governed the right since the late 1970s has been shattered enough that a neophyte such as Donald Trump was able to vanquish a dozen-plus well-regarded former governors and sitting senators without breaking a sweat.

What will be the principles around which new political and ideological coalitions form, especially for Americans under 40? The specifics remain to be seen, but if the gun issue is any indication, those organizing ideas will appear random and eclectic to the aging political class barking nightly on cable news. For those of us who prize autonomy, pluralism, and permissionless innovation, they will make more obvious sense. Younger Americans take a pretty robust social-welfare state for granted, which isn't exactly libertarian dogma, but in many and perhaps most other ways, they seem very comfortable in a world overflowing with choice, personalization, and pluralism. All of that sits well with a broadly defined libertarianism. More on that here.