The clergy chosen by President-elect Barack Obama to pray at his inauguration fill separate symbolic roles: One is a nod to the civil rights activists who made Obama’s election possible. The other is an overture to conservative Christians who rankles some Obama supporters.

The Rev. Rick Warren, who will give the invocation, is the most influential pastor in the United States, and a choice that has already caused problems for Obama.

The Rev. Joseph Lowery, 87, is considered the dean of the civil rights movement. For the benediction at the Jan. 20 swearing-in, he says he will pray that the “spirit of fellowship and oneness” at the inauguration endures throughout Obama’s presidency.