A firestorm of criticism from liberal and gay-rights activists has followed ever since Obama announced Wednesday that Pastor Dr. Rick Warren will give the invocation at the Inauguration. 

Warren, author of The Purpose Driven Life and other books, preaches conservative Christian issues at his large Saddleback Church in Lake Forest, CA. He stresses about climate, poverty and AIDS in third-world countries. But it’s his outspoken opposition toward abortion and gay marriage that has many human-rights activists, lesbian and gay activists finding Warren’s presence at Obama’s inauguration a slap in the face.

Today, Obama is defending his actions saying that disagreeing is what "America is about." SwampPolitics reports Obama saying:

We’re not going to agree on every single issue, but what we have to do is be able to create an atmosphere where we can disagree without being disagreeable, and then focus on those things that we hold in common. So Rick Warren has been invited to speak. Dr. Joseph Lowery who has deeply contrasting views than Rick Warren on a whole host of issues is also speaking during the course of the entire inaugural festivities, there are going to be a wide range of viewpoints that are presented … Because that’s what America is about.

Click here to read the full transcript.

While Obama is saying that we should all hold hands in harmony and live in peace among our "contrasting views" … his selection of Warren is upsetting human-rights groups. The Human Rights Campaign, the largest homosexual rights organization in the U.S., sent a letter to Obama, urging him to reconsider and calling the invitation "a genuine blow." The letter states that Warren was a proponent of Proposition 8. (The proposition, which eliminated the right of same-sex couples to marry, passed with 52 percent in November.)

"By inviting Rick Warren to your inauguration, you have tarnished the view that gay, lesbian, bisexual and transgender Americans have a place at your table," says the letter by Joe Solmonese, president of the group. "We feel a deep level of disrespect when one of the architects and promoters of an anti-gay agenda is given the prominence and the pulpit of your historic nomination."

"Rick Warren has not sat on the sidelines in the fight for basic equality and fairness. In fact, Rev. Warren spoke out vocally in support of Prop 8 in California saying, “There is no need to change the universal, historical definition of marriage to appease two percent of our population … This is not a political issue — it is a moral issue that God has spoken clearly about." Furthermore, he continues to misrepresent marriage equality as silencing his religious views. This was a lie during the battle over Proposition 8, and it’s a lie today." 

Click here to read the full letter.

Kathryn Kolbert, president of the equal-rights group People for the American Way, called giving Warren this honor a "grave disappointment."

"Pastor Warren, while enjoying a reputation as a moderate based on his affable personality and his church’s engagement on issues like AIDS in Africa, has said that the real difference between James Dobson and himself is one of tone rather than substance," Kolbert said in a statement. "He has recently compared marriage by loving and committed same-sex couples to incest and pedophilia. He has repeated the Religious Right’s big lie that supporters of equality for gay Americans are out to silence pastors. He has called Christians who advance a social gospel Marxists. He is adamantly opposed to women having a legal right to choose an abortion.

"I’m sure that Warren’s supporters will portray his selection as an appeal to unity by a president who is committed to reaching across traditional divides. Others may explain it as a response to Warren inviting then-Senator Obama to speak on AIDS and candidate Obama to appear at a forum, both at his church. But the sad truth is that this decision further elevates someone who has in recent weeks actively promoted legalized discrimination and denigrated the lives and relationships of millions of Americans." Click here to read the full statement.