No, it is not. Say I follow a blogger and they repost something from the Dallas Morning News' website. I'll probably read it on the blogger's site and may click on an advertisement on that blogger's site.
I don't regularly visit the Dallas Morning News' website, so if that blogger had never reposted that article, I would have had no idea of its existence, and I would not have visited the Dallas Morning News' website and they would not have gotten any ad revenue.
So:
Blogger re-posts?
Blogger: $0.10
Dallas Morning News: $0.00
Blogger does not re-post?
Blogger: $0.00
Dallas Morning News: $0.00
Is that stealing? No. Is it morally wrong? Yes.
Now, this logic only applies to news sites. News is fleeting, and you are much more likely read it on an RSS feed on a blog you follow or by visiting the news site directly than you are to just search for it. Now, if the reposted content is a product/service/business review or a tutorial or something else that isn't fleeting, this argument goes out the window.