USA 2012 presidential election with tweaks by almccon

index.html

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="//d3js.org/d3.v4.js"></script>
  <script src="//d3js.org/topojson.v1.min.js"></script>
  <style>
    body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
    svg { width:100%; height: 100% }
  </style>
</head>

<body>
  <script>
    var width = 1000,
        height = 800;

    // Note: with d3.v4 we can't use "fallback projections"
    var projection = d3.geoAlbersUsa()
      //.scale(500)
      //.translate([width / 2, height / 2]);



    var svg = d3.select("body").append("svg")

    d3.json("elpo12p010g.topojson", function(error, usa2016) {
      if (error) return console.error(error);
      var counties = topojson.feature(usa2016, usa2016.objects.elpo12p010g).features
      

      var color = d3.scaleLinear()
        .domain([
          d3.min(counties, function(d) { return +d.properties.PCT_ROM}),
          d3.max(counties, function(d) { return +d.properties.PCT_ROM})
        ])
        .range(['blue','red']);
      
      var countyPaths = svg.selectAll("path")
      		.data(counties)
      	.enter().append("path")
      		.attr("d", d3.geoPath(projection))
      		.style("fill", function(d) { return color(+d.properties.PCT_ROM);});

    });
  </script>
</body>