The man presents himself very well. He speaks well, always dressed to the T and has impeccable, some might even say presidential posture. The thing is, he talks out of all sides of his mouth. The man does not seem to have one position; rather he says whatever pleases the audience that he is speaking to. That being said, he seems to be much more consistently in the Center, maybe even on the Left on some issues.
I can see why the Main Stream Media props him up as the next big GOP thing. He fits into the role of "next one in line" in the game political heir apparent. He also fits their agenda. He seems to be easily manipulated if he can smell votes and will bend to the left on a whim. One of the most telling examples of this happened while Mitt Romney was taking questions at a campaign stop in early June where he fielded a question about Global Warming. Here is a video of his response via Think Progress:
This is simply one of the most recent examples. There still remains the big, black cloud looming over Romney's head: RomneyCare. There's no question at this point that RomneyCare set the stage as a template for ObamaCare, as even President Obama himself has said as much. Candidate Romney remains steadfast in support if his decision to give health care to the state in Massachusetts, a egregious move after the outrage that was sparked when the wildly unpopular ObamaCare was shoved down the country's throat, leaving most of Romney's national voting block with more than a bad taste in their mouth about state-run health care. At this point, it is clear that state-run health care is something Romney supports, regardless of his campaign talking points against Obama's plan.
Romney has flipped, or maybe flopped, on other issues important to the Conservative base as well. These issues include abortion, gay marriage, gun rights and fiscal policy. He was Massachusetts governor during "The Big Dig" controversy which was an example of poor leadership throughout his administration, including him. Mitt Romney is a registered Republican, but it ends there. Sure there's a few conservative tendencies mixed in there, but these do nothing but plant him firmly in the middle of the political spectrum which is not what the GOP needs and certainly not what the country needs.
This is but a synopsis of Mitt Romney and why he is not a strong conservative candidate and ought not to be the front runner for the Republican nomination. I would be remiss not to mention a very in depth piece written by @KLSouth on twitter (aka Kelly). I must recommend that you read his piece, "Romney is No Conservative" as soon as possible.