These charts were all made from information from a new Univision Poll. They surveyed 1400 registered Hispanic voters between June 12th and June 25th, and the poll has a margin of error of 2.62 points (slightly higher for only Democrats or Republicans).
Republicans have been worried about the Hispanic vote. George Bush got about 35% of the Hispanic vote in 2000, and barely squeaked into office. he did better in 2004, getting 44%. But the GOP candidates following Bush have done much more poorly -- with McCain getting 31% in 2008 and Romney getting only 29% in 2012. And as the bottom chart below shows, no current Republican can even match Romney's poor showing among Hispanics. Jeb Bush does the best when set against Clinton at 27%, and Marco Rubio is next with only 25%.
Those numbers are not going to work for the Republicans, and that was before Donald Trump started his vicious anti-immigrant rhetoric. It can easily be seen why GOP leaders are worrying about the picture of the Republican Party being painted by Trump. That rhetoric may work in the primary (where only 16% of Hispanics will be voting), but it sure will hurt in the general election. About 58% of Hispanics say they are Democrats, and that rhetoric certainly won't appeal either to the 26% who say they are Independents.
Also interesting is the fact that the overwhelming majority of Hispanics (68%) say a candidate's ability to speak Spanish won't affect who they'll vote for -- so Jeb Bush, who speaks Spanish, won't get much help from that.
The charts below show the presidential preference of Hispanic Democrats and Republicans. Note that Hillary Clinton has a huge lead among Hispanic Democrats -- 73% compared to 8% for Biden and 3% for Sanders. Bush (40%) has an 18 point lead over Rubio (22%), while no other Republican tops 8%.
The bottom chart matches Hillary Clinton against the leading GOP candidates. Bush does the best with 27%, but that is still 37 points behind Clinton (64%).
If the GOP expects to get a respectable percentage of the Hispanic vote in 2016, they have a lot of work to do.