The reason why Senator Obama would be a great choice right away is that he focuses on shared, common values instead of antagonizing political opponents. Particularly in this political environment, that would be an invaluable quality in a national leader.
I think that Senator Obama is young for President by recent standards, experience aside, and that may be unsettling to voters. It certainly would not bother voters if he were on the ballot for vice-president, and I would be very surprised if he is not on every nominee's short list should he take a pass on the top job this time.
He converted from Methodism to Catholocism and is a member of the famous Opus Dei prelature.
My guess is that - whether fair or not - between the Da Vinci Code book and upcoming movie, voters will not be willing to put a member of that group in the White House. I'd put Brownback in the "non-starter" category.
Interesting choice of words, Chris. In the last few months, we created a 527 and website to develop the progressive "bench," which we call DemBench (http://www.dembench.org).
We don't have ideological litmus tests, because we know that what works in New York may not work in Montana. But we're trying to tap into the energy of netroots activists an channel their enthusiasm and support into the races for young candidates for state and local office. Check it out.
I think Chris is very right - Republicans consider being Republican to be a core part of their identity. It is in some ways the same phenomenon that led to the "solid South," and flipped due to Nixon's Southern Strategy -- ingraining in millions of white Southerners that no matter what the issue, there is an US and a THEM, and the Republicans are us.
What Democrats need to do is
build Democratic brand loyalty among progressives and other members of our coalition, so that we can count on them to support us regardless of the candidate or issue.