Trump can win hands down, all he has to do is commit to nothing , just keep hammering on the continuous failure of everything the Dems represent. Socialism, illegal immigration, high taxes, deficit spending weak defense etc.
Personally, while I would have preferred a Cruz, Perry, Brewer, or Walker, I think Trump IS inevitable.
The more the establishment try to cram a mediocre turd like Rubio on the voters the harder they will push back by supporting the perceived "outsider" the GOP and media both hate.