Barack Obama picked evangelical minister Rick Warren for the invocation at his inauguration, and gay activists are furious.

Barack Obama’s choice of a prominent evangelical minister to perform the invocation at his inauguration is a conciliatory gesture toward social conservatives who opposed him in November, but it is drawing fierce challenges from a gay rights movement that – in the wake of a gay marriage ban in California – is looking for a fight.

Rick Warren, the senior pastor of Saddleback Church in southern California, opposes abortion rights but has taken more liberal stances on the government role in fighting poverty, and backed away from other evangelicals’ staunch support for economic conservatism. But it’s his support for the California constitutional amendment to ban same-sex marriage that drew the most heated criticism from Democrats Wednesday.

“Your invitation to Reverend Rick Warren to deliver the invocation at your inauguration is a genuine blow to LGBT Americans,” the president of Human Rights Campaign, Joe Solomonese, wrote Obama Wednesday. “[W]e feel a deep level of disrespect when one of architects and promoters of an anti-gay agenda is given the prominence and the pulpit of your historic nomination.”