I'm assuming groups will continue to vote at abut the same rate for a party unless something causes them to change. Why would you assume Hispanics would start voting more GOP if Rubio was elected? Obama was elected but the percentage of blacks voting for Democrats didn't change much. If Ben Carson is elected the percentage blacks voting GOP won't change much.
To get people to start voting for you you have to start appealing to them.
Once again, I could easily see a dramatic change in Hispanic voting patterns with a Rubio presidency. Just as Ronald Ragan fundamentally changed the landscape in the 80s Rubio could do something similar . I'm not saying that he will but it is certainly possible. Keep in mind Hispanics to tend to be very conservative, socially. In a company which I partially owned, we employ more than 50 Hispanics. They want illegal immigration stopped as much as anyone. The reason? Wages. Why would you pay a construction worker 20 bucks an hour when you could easily pay any illegal immigrant 10 bucks an hour.