As expected, the GOP "leadership" caves. Romney's limp-wristed counter punch is that Obama's amnesty was "political."
Even if Rubio's bill were to state that they must have entered the USA before the age of 16, they can't vote, and no chain immigration:
1) Once Rubio's bill enters the congressional process, Dems (helped by Rinos) will do their damndest to strip out any limitations Rubio started with, and to add not only new and bigger amnesty "features," but also miscellaneous porky surprises. The only way that could work out OK is if it is voted down, but they never give up.
2) In the slim-to-none-probability category, Rubio's bill actually makes it though congress with no chain immigration and no voting for the Dream Act beneficiaries. Now they have a big foot in the door. Leftist judges start ruling that, since other amnesties allowed "a path to citizenship," this one must also. If Obama is POTUS in 2013, he just ignores the parts he doesn't like. Who knows what Romney would do, but I would not count on him stopping deportations or "securing the border."
3) Expect rampant fraud to "prove" that they were here before the age of 16 and to satisfy other requirements. And don't expect the Mexican Govt. to report criminals and terrorists. They want all of them to be working in the USA.
4) I won't bother to repeat the details of the insanity of giving out work permits, especially in the midst of high unemployment.
5) The message to families in Lantin America, Asia, and the rest of the 3rd world: Bring your kids to the USA, and don't bother with trying to do it legally.