All along the U.S.-Mexico border, about 840,000 mostly low-income, immigrant Latinos have settled in colonias – cheap plots of land outside city limits without basic infrastructure such as water and sewage systems, electricity and paved roads.

With the presidential election less than three months away, millions of Americans will be navigating new requirements for voting – if they can vote at all – as state leaders implement dozens of new restrictions that could make it more difficult to cast a ballot.

When Arizona voters approved medical marijuana in 2010, the traditionally conservative state did so tentatively: The “yes” campaign garnered 50.1 percent of the vote. State officials now call Arizona’s system a model for other states,and members of the pro-legalization campaign deem the system a big success.