The media launched a smear campaign on Newt when he was Speaker, the kind of campaign that started with Bork. People didn’t get savvy to how badly the media spun things towards liberals until the conservative media got started with the internet, talk radio, FOX News in the late ‘90s and to today. It’s a very different environment. Most likely the average person has a negative meme implanted in their heads from that era, like they would for Ken Starr, Linda Tripp, even Rush Limbaugh. But just like Rush, if Newt got the chance to make his case on the national stage he would be able to bring people over to his side and change their minds about who he is and what his positions are. Obviously you know how most people who don’t like Rush will readily admit they never listened to his show.
I think you're right in your analysis, and that this could happen.
However, it's not clear to me that Newt HAS changed ("fundamentally," as he loves to say). I would love it if he had, but I don't see it yet. Also he is playing to the crowd and that is causing him to highlight the very type of political persona that garnered him "Most Hated Politician in the World" status back in the 1990's.
IOW, the reason Rush always wins over the uninitiated is because he actually IS a lovable little fuzzball. Newt? Not so much.
If we end up nominating him, though, he surely is going to have to become a whole lot more likeable before he has a chance of winning the general. Of course, many in the conservative sphere are actually working against that by lauding him more the more unlikeable he is!
And don't get me started on Callista. UGH. Moreover, it's not clear she's committed to giving up her life as she knows it now to be First Lady, and that would be a horrible complication for any man, much less one on his third marriage.