Let’s deal with first things first: The notion that there’s “not the slightest bit of evidence” that Hispanics are going to vote Republican is quite wrong. George W. Bush won roughly 40 percent of the Hispanic vote in 2004.40% is a lot less than the 60% who voted against him. Romney got about 30% of the Hispanic vote.
Bush was a popular Texas governor and a lot of Hispanics live there. Since then, elections have become more demographically polarized, with Democrat success dependent on aggressively pursuing the non-white, unmarried, non-Christian, and low-info voters.
But it is not true that Hispanic voters were decisive in electing Barack Obama in 2012. While the Hispanic population is growing rapidly, most of them did not vote, and those that did are concentrated in non-swing states like California and Texas. The Hispanic voters could have made a difference in Florida, but not so much elsewhere.
If an illegal alien amnesty is passed, then Democrats are likely to get a huge voter windfall.
Update: Steve Sailer reports that that major news media told us that the 2012 election voters were 10% Hispanic, but it was only 8.4%, according to Census figures.