It doesn't matter whether the GOP would reject Obama's offers or not. The point is as a "Democrat" he is willing to sell "entitlements" down the river is the point. It is anathema to traditional Democratic Party principles.
Take a look at the record and try to argue with a straight face Obama is a Democrat.
It's all a bunch of theater anyway. The Republicans have gone into batshit crazy territory, while Obama is so far to the right he is bordering on being a fascist. The elites get what they want anyway regardless of the letter after somebody's name.