One way to think of Mitt Romney's multiple, evolving personalities is as software iterations. Software companies often release a usable product, but then push out updates over time. So it is with Romney, who has been continually patched and upgraded over the course of the campaign.

The version of MittRom.ney that showed up last night was the best version I've seen so far: quicker, more responsive, more feature rich, less awkward and phony. He offered a convincing simulacra of presidential poise and was able to avoid many of the bugs that have plagued him in the past. It was a good demo, in other words, and I think it's pretty clear that he won the debate. (More on this in my column later today.)

But the latest update to the GOP candidates operating system still outputs problematic responses when it comes to health care. At the debate last night, Romney was asked how he would replace ObamaCare after repealing it, as he has promised he would do. In particular, he was challenged to explain what would happen to individuals with preexisting conditions. Romney, as his is wont, described his health care plan via a numbered list. The first item: "Preexisting conditions are covered under my plan." 

We've been through this before. And it's generally been clear that when Romney claimed to cover preexisting conditions under his plan, what he was actually doing was promising to keep in place protections that already exist in the law for those who have preexisting conditions but maintain more or less continuous coverage. 

But Romney added a new element last night. When Obama challenged Romney's assertion that he actually covers preexisting conditions rather than simply keeps existing law in place, Romney shot back with this interesting reply:

And with regards to health care, you had remarkable details with regards to my pre-existing condition plan. You obviously studied up on -- on my plan. In fact, I do have a plan that deals with people with pre-existing conditions. That's part of my health care plan. And what we did in Massachusetts is a model for the nation state by state. And I said that at that time.  

Romney is right to distinguish between federal and state plans. But the difference here mostly is a difference in degree, not in kind. And it is not much comfort for those who think that both plans are problematic. What Romney seems to be saying is that he would repeal ObamaCare, and its preexisting condition exclusions, and instead have states set up their own versions of RomneyCare, which has essentially the same preexisting condition regulations as President Obama's level. The only difference is that the rules would be enforced at a state level. And if that's the case, then that leaves more states open to an insurance mandate, just like the one in Obamacare, just like the one Romney signed off on in Massachusetts. Romney may want to repeal ObamaCare, but it seems very much as if he would prefer to replace it with a state-by-state version of the same thing. 

Romney, who reportedly chose his chief campaign strategist in part because he was the only one who said he could continue to defend the Massachusetts health plan, can't seem to let this one piece of his legislative history go. What we saw last night was, in many ways, an upgraded Romney. But on RomneyCare, he's still stuck at version 1.0.