The president shouldn't being doing this by executive action, that's for sure. I'm not sure what he's up to this week -- it sounds like he's trying to disrupt the narrative. Every time he pulls something else out of his sleeve (net neutrality, climate change treaty, immigration) that becomes the story. Otherwise, what would everyone have been talking about this week? How the Republicans swept the election and how bad of a shellacking the president's party took. I think he's trying to mix things up and take people's minds off the election.
The Republicans should just pass whatever immigration bill they can get through the Senate, and tell Obama to either sign it or veto it. If he vetoes it, they can say he preferred his own executive actions to Congressional legislation on the exact same topic, which wouldn't give him much of a leg to stand on. He pretty much has to sign whatever immigration bill Congress sends him now.
Why not? If it's sensible policy and he has the legal authority, why not? If Congress doesn't like it, they can change the law. That's how government is supposed to work.
Did you feel that way when Dub sat in the Oval, bedstuy? Be honest.