Has Trump not run, who would have won the Republican nomination?

[Free Bird]

Rubio easily, and he would have lost in the general

Yeah no. Almost any Republican would've crushed Hillary, and Trump was the least decisive of them all.

With that said, Rubio would've secured the nomination and gotten between around 330 and 380 electoral votes.

That's simply not true...what States could Rubio flip from 2012 to beat Clinton? Maybe Nevada, maybe New Hamsphire, that's not good enough... in the primary the guy lost every county in Florida to Trump besides Dade, so I doubt he would have flipped his home state either. Cruz wouldn't have flipped anything, he's even less likable than Clinton and Kasich would have only flipped Ohio and maybe the Moderate suburban Republicans in NOVA. 

He was also reelected on the same day in Florida by almost ten times the amount Trump won by. To dismiss the idea that he wouldn't have flipped his own damn state when he won 47% of hispanics is foolish. That number, by the way, would have easily given him Colorado and maybe New Mexico. With your own concessions, that's 259. I agree he wouldn't have flipped the closer WCW states, but Hillary was a terrible fit for Ohio, so there's that, and his potential youth appeal may narrowly give him Iowa. 283 right there. Not as generous as some would think, but he still wins, and will still be a very strong nominee if ever nominated when he inevitably runs again, especially if it's in 2028 if Trump loses in 2020, or 2032 if he is reelected.