The polls and headlines say it repeatedly: Evangelicals overwhelmingly support Donald J. Trump for president.

But now, a group of more than 75 evangelical leaders has released a declaration saying that those polls and headlines do not speak for them. The group includes African-American, Asian, Hispanic and white evangelical Christians, and it says that the news media and the polls are overlooking nonwhite evangelicals.

Nonwhites make up about a quarter of evangelical Protestants in the United States, according to a study released in 2015 by the Pew Research Center. They are a growing segment of evangelical Christianity in the United States, and they can be found worshiping in their own ethnic churches and as part of racially mixed congregations.

The declaration, released on the website Change.org on Thursday, accuses Mr. Trump of fueling racism and religious bigotry, and of denigrating women. It is not concerned with Mr. Trump’s playboy past, multiple marriages or lack of fluency in Christian language and practice.