Why? It's legal under HI law and seems like a good move for the GOP to try and make this seat competitive. It doesn't seem as the Dem machine in HI would support Case fresh off beating Akaka. But sure as hell the GOP would rally around Aiona.
Nobody thought of it because Case is even stronger in the general then Akaka (among other reasons).
Actually, polls show Akaka doing better than Case in general election match ups.
Which polls? I've only seen Rasmussen and they have Case doing slightly better in the general with 61%. Akaka had 58%. Either way, either one will win the general election easily.