My guess is that it is doable.
I see it this way. Democrats will want a path to citizenship.
And the few republicans who do support it ( Like Senator Mccaine) will most likely will only vote for temporary few years worker visa.
And then " path to citizenship" will become the new " public option".
Also do not worry. There will be talks next year even if they are not enogh votes. Many caucasus will push for it, the same way as they pushed for public option.
Lets not forget , it is not just the hispanic votes at stake here. Many other ethincities want for immigration reform to pass. Although maybe few people are undocumented immigrants, many of their family members and relatives are citizens who strongly support it.
Immigration reform is much more important issue that media has covered it to be to politicians.