Rubio’s just trying to rehabilitate his image with conservatives so he can run for higher office in the future. I hate panderers, especially when they think they can pander to me.
Basically, Rubio is trying to prove that he represents a sane "middle ground" between Obama's amnesty and "extremists" who oppose a "path to citizenship." Trying to highlight the alleged differences between his proposal and Obama's is just a ruse to hide the fact that Rubio and Obama differ in rhetoric, not substance, and that there is no "middle ground" on the issue: either you favor amnesty, or you support enforcing existing immigration laws. Period.
I know what you mean though about pandering and rehabilitation. A lot of people on this site are sold on Sarah Palin's newly minted opposition to amnesty, conveniently forgetting and forgiving the fact that she was all for it as McCain's running mate 4 years ago.