What makes you think Mittens isn't capable of all those same excesses, usurpations, bypasses, edicts, and leftist appointments? He clearly demonstrated that he is, while he was Governor of Massachusetts. I defy you to point to a single substantial thing in his record that differentiates him from Obama, or any other left-wing radical.
Pushing the fear button is ineffective on anyone that can see this.
I personally don't see Romney being as bad as Obama - but if he has GOP control of the House and Senate as well, without an influx of additional conservatives into both bodies, some of that difference could well be offset.
Like I said, every conservative is going to have to sort through this for themselves, but it isn't nearly as black-and-white as people on both sides are making it. Obama is a known. Romney is far less of such. So everyone will have to try and guess for themselves how Romney would act as president.