For several reasons, it's hard to see the modern secular movement as a passing phase that will be gone tomorrow. The movement may level off, and even experience ebbs and flows over time, but the emergence of seculars resulting from the modern secular movement is highly unlikely to reverse itself, and the impact of that emergence is likely to be lasting and profound. Here are five factors indicating that the contemporary trend of secularity should have long-term traction:

1. The secular demographic won’t disappear

Secular Americans are a broad tent that includes not just atheists and agnostics, but millions of Americans who are simply not religious. These are good, taxpaying citizens who are generally skeptical of grand theological claims, who wouldn’t dream of spending Sunday morning sitting in church, and who tend to see church-state separation as important. These seculars have always been around, and there is no chance that they are suddenly going to disappear.

Indeed, if the secular movement seems like a new phenomenon (and it is), that’s because many of these nonreligious and nontheistic Americans have only recently begun to appreciate their secular . By remaining in the closet for decades as the religious right was growing into a major political force, seculars inadvertently helped create a landscape ripe for anti-intellectualism and disastrous public policy. The modern secular movement can be understood as a response to that mistake, taking root as seculars increasingly realize that they must be “out” and visible in order to fight back against the religious right.

About one in five Americans are now religiously unaffiliated, and many more are simply apathetic towards religion. Trends seem to suggest that those numbers will only increase, but even if there is some fluctuation it seems unlikely that the demographic will shrink to insignificance or suddenly become ambivalent about its agenda.

2. The Internet and social media have changed everything

A generation ago, if you were an nonbeliever living in, say, Columbia, South Carolina, you may have thought you were the only one for twenty miles in any direction. Today, however, by using tools such as meetup.com, you can quickly discover that there is a group called the Freethought Society of the Midlands, with almost 400 members. Thanks to the Internet and social media, seculars are identifying openly, finding community, and connecting with one another in ways that simply were not possible just a few years ago.

Through the Internet, America's religious skeptics are discovering that their views are shared by millions of others, and that there is strength in numbers. When high school sophomore Jessica Ahlquist challenged a prayer banner hanging in her public school in 2011, she was met with great hostility from her community, but she found much camaraderie online. A Facebook group formed to voice support for her effort, and thousands joined. Such solidarity among seculars was nonexistent before the Internet, but is widespread now and unlikely to disappear.

3. Seculars are organized

There are numerous national and local groups promoting the interests of nonreligious Americans, and these groups are attracting resources like never before. The Secular Student Alliance, for example, the national umbrella organization for campus atheist-humanist groups, was formed just a decade ago and has seen spectacular expansion in recent years, growing from a few dozen affiliates to over 400. Now the SSA is setting up atheist-humanist groups in high schools, a move that is sure to normalize atheism and humanism at the grassroots level. Secular Americans now also have a formal lobbying organization in Washington – the Secular Coalition for America – which has launched a grassroots initiative to lobby in all 50 states as well. Other groups, such as the American Humanist Association, American Atheists, and the Center for Inquiry, all of which have been around for decades, have committed to activism and secular visibility in ways that they didn’t years ago. These groups provide professionalism - advocacy, educational materials, lobbying, communications, etc. - that enables seculars to nurture and expand their movement.

4. The ideas underlying secularism are modest, not radical

No matter what you think of the central assertion made by the secular community – that a good life can be attained within the framework of the natural world, without reliance on claims of beliefs – it's hard to call it unreasonable. In fact, the ideas underlying the secular movement, if fairly considered, are actually quite modest, even humble.

Bearing in mind that all the major western religions claim not only that God exists, but go far beyond that to assert the notion of divine revelation (that is, that God communicated with ancient prophets and revealed fundamental truths to them), one can understand the secular movement as simply reflecting a modern realization that such claims seem implausible, that ethics and inner peace can be achieved without divine revelation. Unlike the clerics of traditional religion, seculars do not claim to have found that elusive concept known as “Absolute Truth.” Disagree with seculars if you will, but it’s hard to call their naturalistic approach patently unreasonable.

If the secular movement were constructed on a foundation of complex and esoteric ideas, its survivability as a meme would be questionable; but given its simplicity and applicability to everyday life, there is little reason to think that it will fade into history due to lack of relevance or interest.

5. Seculars are finally demanding equality

Although seculars have been around for a long time, they have almost never asserted their rights as a minority demographic – until now. Having finally grasped the concept of equal rights, there is no chance that this large, increasingly cohesive bloc is going to back down.

Historically, even if some seculars would occasionally push back against the influence of conservative religion, their arguments would almost always be made from the standpoint of enforcing the “wall of separation” between church and state. Never would seculars demand that, as a matter of social justice, they stand on equal footing with those adhering to traditional religion, that against them is wrong. Now, however, we more frequently see seculars reminding the public that nonbelievers are Americans too, assertively rebutting the “Christian nation” rhetoric of conservative politicians. In Massachusetts, the first-ever lawsuit enforcing atheist-humanist rights solely via the avenue of equal protection – rather than via the church-state arguments of the Establishment Clause – is heading to the state’s Supreme Judicial Court this year, and increasingly Americans are seeing and hearing atheists-humanists use the language of equal rights. Don’t expect it to subside.

David Niose’s new book, Nonbeliever Nation: The Rise of Secular Americans, is available here and wherever books are sold.

Follow David Niose on Twitter