Giuliani's criticism doesn't surprise me; you'll recall that there was no love lost between him and Romney back in 2008 (nor does one get the feeling that the former mayor is the type simply to forget those kinds of things). And Sarah Palin was, as Guy notes below, directly asked about Romneycare.
But what is surprising to me is the effort, in some necks of the conservative woods, to strangle the Romney campaign baby in the cradle. Why the seeming attempts to shut down a Romney run preemptively?
Yes, we all know that he's shifted some positions over the years (so has any politician whose been in public life for more than ten years -- and so have those who supported him in 2008 but are disparaging him now). Yes, Romneycare included the hated individual mandate (albeit on a state, not national, basis). Unfortunate, yes. Sub-optimal, yes. But come on.
On the other hand, Romney has loads of executive experience. He's survived the exigencies of a presidential campaign before. He can raise money. And he understands the economy and how to create jobs -- and, given his background, will be perceived as such by "normal" voters who are less concerned with conservative "purity." The Democrats get that, and they fear it.)
Those are not small assets. Maybe a better candidate will emerge. But others, who attract a more passionate following, have some troubles of their own (including those who, like Herman Cain, I kind of like).
So let's not start trying to run credible, mainstream candidates out of the race prematurely (except for any who join President Obama in dumping on the GOP's current legislative platform). Let's let a thousand flowers bloom.
Yes, let's find the most conservative candidate. But equally important, let's also make sure he or she is the most conservative candidate who can actually defeat President Obama. Times are too serious -- and the country's straits are too dire -- to allow President Obama to win reelection simply because Republicans weren't smart in choosing a candidate to oppose him.