Only citizens can vote in federal elections. Non-citizens can not vote regardless of their legal status.
The political risk is people who are identified as Republicans making anti-Hispanic statements that will alienate all Hispanics, even the ones whose families were here before the American Revolution.
And we are talking about a plan that will allow all these "guest workers" to become legal citizens.
I don't have a problem with that per se. But to say that the national partys don't see the votes that could be counted on in the future is naive.