Rubio will never be president.
Next up will likely be Hillary.
In fact, I think it's incredibly unlikely that we'll EVER see another Republican/Conservative president.
There is NO upside for Republicans on this issue. Once the Immigration Bill comes out, Republicans will either fall all over themselves pushing for it (and alienating their base) or running from it (alienating Hispanics).
And when it passes, Obama will get the credit, and the Dems will point out that they had to drag the Republicans kicking and screaming to get it done. No matter what, the Dems win, and you can kiss Florida and Texas goodbye. There's no way a Republican can win without Florida, much less Texas to boot.