Is there enough evidence yet to suggest that Trump is indeed unelectable?
If you're referring to his favorables (I assume you are as his vote shares aren't too bad) then it is worth pointing to the fact that a large number of Republicans view him unfavorably. If/when he clinches the nomination his favorables will probably surge to the low to mid 40s or so as a rally-around-the-party effect. Hillary is already viewed favorably by like 80% of Dems so she will only get a small bounce in her favorables.