The economic policies are basically people voting to preserve their livelihoods and develop their communities economically. Queensland and WA both have vast swathes of land where people living there have very few options when it comes to earning a living.
The anti asylum seeker and anti Aboriginal attitudes are borne out of the isolation and homogeneity of their communities, as well as the fact that the general population in these areas have less education than the cities. We're talking about the whitest, least educated areas in Australia, which narrows people's worldviews somewhat, to the point where their preferred solutions to policy problems don't involve abstractions like social justice or depend so much on stuff like statistical analysis, but are pragmatic and concrete, here-and-now fixes.
Look at Bob Katter'a fixation on ending Woolworths and Coles' duopoly on food retail. He sees two dragons to fight and proposes to go up the mountain and kill them, rather than trying to address the conditions that made that mountain such an attractive place for dragons to congregate in the first place.
A farmer or grazier sees him or herself as a steward of their own land. After all, the farmer who fails to look after their own land exhausts it quickly and bankrupts their business, failing to pass it on to their own kids. This is why they resent these big city greenies who come in and tell them that because of aggregate overuse of the fresh water supply, everyone suffers and desertification and salination are taking place. The farmer resents this because to them, it's as Ann as the nose on Plain's face that the fastest way to get desertification and salination happening on their own land is to stop using water on it. What does this greenie know about farming?
It's the same attitudes that shape views, among white rural Australians, of the welfare state and the services it provides. As far as they're concerned, welfare is for the lazy and services are for the cities. In the here and the now, they don't see the intangible benefits of having a healthy welfare state, not in their own lives nor in those of their friends. As far as they're concerned, their hard earned tax dollars are being unfairly siphoned out of their own pockets and being given to the undeserving or to the cities.
This leads into the prevalence of anti Aboriginal attitudes. In the cities, Aboriginal people have more educational and employment opportunities, more support and more hope, so our exposure to the social problems facing their communities is somewhat lessened. In the country, and especially in more isolated places, these factors don't come into play, so a white country person's exposure to Aboriginal people can often be far less positive.
Perhaps on account of the isolation intrinsic to life as a farmer, people in rural areas tend to rate self-reliance as much higher on the list of virtues than a city person would. This attitude leads people to see one's success or failure in the face of adversity to be a reflection on one's own moral character. This means that they're a hardy and tenaceous lot out there. The trap here, however, is the inability to see the historical and systemic forces that perpetuate the problems in Aboriginal communities and instead see these problems as the culmination of a thousand individual moral failures of the affected Aboriginal people themselves.
Why should we give any special rights or even recognition, they reason, to a bunch of drunken, violent layabouts? They have every chance, they think, to lift themselves out of their situation, clean themselves up and get a job, but they fail to do so consistently. Nope, the thinking goes, they haven't earned the right to even be treated like equals.
Asylum seekers get it even worse, because not only are they coming and taking up tax dollars, but they're also foreign, which means they could be bringing problems into the country that haven't even been dreamed of yet.
TL;DR - The Queensland and Western Australian electorates love them some bootstraps and distrust city intellectuals on account of their pushing impractical pie-in-the-sky schemes onto their practical, self-reliant communities.