I think there is a difference here in that Obama has a background of involvement in extreme left wing politics, being a disciple of Saul Alinsky, his ties to ACORN, Bill Ayers, Jeremiah Wright, etc. I think there is cause for concern. I suppose he might moderate and mature in office, but I think Conservatives should have some healthy scepticism.
That's a perfect example. As I noted during the campaign I thought this was an issue McCain should have raised. But not in the context of he's a communist/muslim/racist/Jewhater, rather that he's comfortable in their company, a clear reflection on his judgement. And I think it's fair to say that his appointments have been wanting, not because they're communists/muslims/racists/Jewhaters, rather because he's a poor judge of talent and overlooks character.