The president won narrowly in Maricopa county in 2016. Polls show his support is draining – and fellow Republicans are at riskIn the agonizing days after the 2018 election, Christine Marsh, a Democratic candidate for state senate in a traditionally Republican suburban Phoenix district, watched her opponent’s lead dwindle to a few hundred votes, with thousands of ballots left to be counted.In the end, just 267 votes separated them.Marsh lost. But the result was ominous for Republicans, in a corner of Phoenix’s ever-expanding suburbs where Barry Goldwater, the long-serving Arizona senator and conservative icon, launched his presidential campaign in 1964 from the patio of his famed hilltop estate in Paradise Valley.series linker embedIn the decades since, population growth and shifting demographics have transformed the cultural, political and economic complexion of the region.And the election of Donald Trump has exacerbated these trends across the country, perhaps nowhere more dramaticall...