I felt at the time and still, 24 hours later, feel that Rick Warren's prayer overall was nowhere near as awful as I'd expected (in fact I was actually sort of impressed by it), until he started in on the Lord's Prayer.
I don't feel the inauguration, or any other civic event in this country, is the place for that prayer for one simple reason:
Though Warren was invited to pray as a Christian and from his Christian faith, he was praying on behalf of all those gathered (just as any person who prays in public is praying on behalf of the congregation, not just him/herself). In this case, all those gathered included the 2 million who were present as well as many millions more who gathered via television all around the world. And when he began to pray a prayer that only a portion of us could pray along with, he crossed the line. He was no longer praying the prayer of the people, he was praying the prayer of the Christian. And, though I am a Christian, I still found that to not be okay, because now my brothers and sisters around the world who were gathered to pray (or not, if that's not what they do) had to stop praying with us because it was clear that it was OUR prayer, not theirs.
Whether it's a part of his tradition to end every prayer, even invocations, with the Lord's Prayer (which I highly doubt--every prayer? really?), is up for debate. And even if it is, I'm not sure it would have been okay in this situation--every tradition is fluid, every tradition rises to the occasion it finds itself in, and this occasion required praying on behalf of millions of people, many of whom couldn't pray along with him anymore at the end.
And that's why I'm saddened that he chose to use one of the highlights of our faith in a venue that excluded rather than included. The end.
In other news: when are we going to insist on calling it an "opening prayer" rather than an invocation (the purpose of which is to invoke, to call in, the presence of God) when that's not really what's going on?