I know a little about IP law (probably just enough to be ‘dangerous’ - grin). If NObama didn’t register a trademark for ‘Hope and Change’ as a tagline or logo, etc., I don’t believe he has any IP claim. And, because they’re generic words, I don’t believe they could be TM’d. Some might consider them descriptive words - for TM registration they would have to have acquired distinctiveness because they were used exclusively by his campaign for a long period of time, which isn’t the case, so I don’t think he could register a TM. Plus, TM registration takes about 1-2 years. I also don’t think those 2 words would be sufficient to be considered copyrightable material. Just my $.02 - all of this would need to be confirmed by an attorney who is an expert on IP law.
Wonder if the IP owners of Bob the Builder - can we build it - ‘Yes we Can’ and/or by the copyright owner, Allen Toussaint - 1970, of the song, ‘Yes We Can’ mind Obambi using those words.
I think you are right on about the "hope and change" phrase, its like owning "have a nice day" just won't happen.