Will Saletan of Slate penned this excellent piece on the rise of Trump, and how many in the GOP are blaming President Obama for his ascension in their own party. Saletan argues, rather well I'll add, that Trump is the GOP's own doing.
In Trump, Republican voters have found their anti-Obama. Trump spurns not just political correctness, but correctness of any kind. He lies about Muslims and 9/11, insults women and people with disabilities, accuses a judge of bias for being Hispanic, and hurls profanities. Trump validates the maxim that in presidential primaries, the opposition party tends to choose a candidate who differs temperamentally from the incumbent. Obama is an adult. Therefore, Republicans are nominating a child.
Why would the GOP be searching for an anti-Obama? What's behind their obstructionism and vehement opposition to every proposal he's made, even the ones that would be praised if they came from the right? Saletan stops short of speculating, but I think its pretty evident to the reader what he is implying.
If you ask me, the motive for the GOP's condemnation of Obama are clear.