There are two variables that may turn out to be at odds with your prediction.
-At this point we don't have a Reagan, or something approximating a Reagan
-Up until now, the GOP has never shown the intestinal fortitude to be proactive and exploit her weaknesses and the virtually unlimited baggage she carries. And it won't until it stops worrying about how her handlers will play the "little woman" card.
Yes, she is very defeat-able, but not by the spineless GOP that we currently have. Unless the RNC grows a pair, she will be viable and electable. No need to play dirty, just repeat the truth loud and often. A skill the current GOP is sorely lacking.
You are so right. Whichever Republican candidate has the guts to play dirty and fight hard against her will get my vote. I just don’t see how she can win a national election. If they treat her like the “little woman” then we are sunk. We are all sick of the limp wrists of the Bush administration.