I posted on Copyright Litigation blog the same video without seeing your post about an hour later, my source was a Google alert on "Nazi & art" that I run daily, my analysis and feeling was exactly the same.
I have noticed that when I seek to post a link from some publications, they automatically insert an enclosure link for my blog post. An enclosure link is a unique link that corresponds to my blog post.
That means if someone tries to click on the link to my blog post, they would be redirected to the newspaper, not to my blog. That's overstepping, and too high a price for a blogger to pay.
I now delete these "suggested" enclosure links, but put a link to the content in the body of my post. I have never run into the ad issue, but don't usually repost content in full.
In the context of an election, campaigning against your adversary is pure political speech at the core of the First Amendment. The First Amendment forbids Congress from passing laws that abridge free speech. Copyright law does not protect "facts". Reid's re-publishing his adversary's political positions is pure First Amendment speech, and falls squarely in the statutory definition of what is NOT copyright infringement (fair use) "for purposes of commentary, criticism, etc.". The statute says that you can publish to criticize, that's what Reid is doing.
So the First Amendment and the actual text of the Copyright Act expressly authorize Reid's publication of Angle's website.