Decent high-voltage DC lines can move that power around with pretty small losses. (Wikipedia quotes about 3.5% per 1000km.) And the Southwest doesn't have to destroy all their natural environments; they just happen to have a natural advantage in power generation on land that otherwise isn't economically productive. (Not that all land has to be economically productive.)

This could be a major industry in those states.

Ecological impact should be looked into and installations should be done in a way that creates minimal environmental impact, but I'm not going to say that it should be an absolute showstopper if sagebrush is interspersed by the occasional array of black panels.

The environmental costs of major solar farms aren't going to be zero, but just because it's non-zero doesn't mean we shouldn't do it if it's environmentally preferable to burning coal and natural gas.

I'm also not against nuclear, I'm just not optimistic we can get the costs down.

While the losses aren't too big, transmission lines are very expensive and take many years of planning to get the land rights required if there isn't already a transmission line going there. There aren't currently a lot of lines going to the middle of nowhere, except for some hydroelectric dams.