Slightly more than 75 percent of American adults identify as Christian, a 5 percent decline from 2008, according to a new Gallup poll released today.
Gallup polled more than 174,000 adults and found that the number of Americans who identify as Christian has fallen from 80.1 percent in 2008 to 75.2 percent in 2015.
While fewer Americans are associating themselves with Christianity, the survey also found that 19.6 percent now have no religious affiliation, a 5 percent increase from 2008.
Despite the changes, America is still a predominately Christian country, with 94 percent of those who identify with a religion saying they are Christian, said Gallup.
"The general trends in the data over this eight-year period are clear: As the percentage of Americans identifying with a Christian religion has decreased, the percentage with no formal religious identification has increased," wrote Gallup editor-in-chief Frank Newport.
Half of those who identified as Christian said they align with Protestantism or another non-Catholic Christian denomination, while 24 percent identify as Catholic and 2 percent as Mormon.
Gallup found that younger Americans were the most likely to report no religious affiliation, with only 62 percent of those 18 to 24 saying they are Christian, compared to 31 percent who did not identify with any religion. Among those over 50 years old, more than 80 percent said they are Christian.
"One key to the future of Christian representation in the U.S. population will be shifts in the religious identification of today's youngest cohorts," said Newport. "Traditionally, Americans have become more likely to identify with a religion as they age through their 30s and 40s and get married and have children. If this pattern does not occur in the same way it has in the past, the percentage of Christians nationwide will likely continue to shrink."
Christian Americans are expected to play a key role in the Republican presidential campaign, particularly in Iowa. A new CNN/ORC poll released Wednesday found Donald Trump still leading the field nationally with 39 percent, and also leading among white evangelicals, with 45 percent. Texas Sen. Ted Cruz has jumped ahead of Trump in Iowa in recent polls with the help of evangelicals, but lagged behind in second place in CNN's poll, with 18 percent in national and evangelical support, noted Politico.
The poll was based on telephone interviews conducted from 2008-2015, with a random sample of adults aged 18 and older and a margin of error of plus or minus 1 percentage point.
