Atheism and secularism are becoming more prominent in the United States, reflecting significant shifts in religious affiliation and belief. As of 2021, about 29% of U.S. adults identify as religiously unaffiliated, which includes atheists, agnostics, and those who describe their religion as "nothing in particular" Pew Research Center. This group, often referred to as "Nones," has grown substantially from 16% in 2007 to 28% in 2023, making them the largest single religious group in the country NPR.

The percentage of Americans who believe in God has also declined, from 98% in the 1950s to 81% in 2022, with only 68% of those under 30 affirming belief in God The Conversation. Additionally, fewer than half of Americans were members of a church, synagogue, or mosque in 2021 The Conversation.

Politically, atheists and the religiously unaffiliated tend to lean heavily towards the Democratic Party, with about 80% of atheists identifying with or leaning towards it Pew Research Center. This demographic is also less likely to be civically engaged compared to their religious counterparts, being less likely to vote or volunteer in their communities NPR.

Despite the growing number of non-religious individuals, atheism remains a taboo in American politics. Nearly 88% of Congress members identify as Christian, with only two members openly identifying as non-religious The Economist.

The future of religious affiliation in the U.S. suggests that if current trends continue, Christians could make up less than half of the population by 2070, while the percentage of religiously unaffiliated individuals could rise to between 34% and 52% Pew Research Center. This shift is influenced by factors such as age, fertility rates, and the transmission of religious identity across generations.

Overall, the data indicates a significant trend towards secularization and a growing number of individuals identifying as atheists or religiously unaffiliated in the United States.