And it's important to note that Siena's polls for Senate races last year were biased toward Republicans. They had McSally and Heller winning, as well as having Cruz up 8%.
This is a pollster connected the New York Times who employers Nate Silver who went off on Twitter using the right-wing slang ""libs". Not sure it's wise to buy into these polls considering that.
They were the single best pollster of last cycle. And yes, Democrats over perform their polls in heavily Hispanic areas. This is known.