diff --git a/src/scripts/censusLayer.js b/src/scripts/censusLayer.js
index 65c6648..9df430a 100644
--- a/src/scripts/censusLayer.js
+++ b/src/scripts/censusLayer.js
@@ -277,31 +277,29 @@ define([
 			   		});
 
 					var self = this;
-				    $.each(geojsonLayer._layers,function(idx,layer){
-                                        var feature = layer.feature;
-                                            layer.feature.map_mouse_over = false;
-                                            hoverTract.watchForValue(feature.id,
-                                                         function() {
-                                                             layer.setStyle(self._styleFunction(feature, true));
-                                                         },
-                                                         function() {
-                                                             layer.setStyle(self._styleFunction(feature));
-                                                         });
-					    layer.on("mouseover", function (e) {
-                                                hoverTract.select(feature.id,
-                                                                  feature,
-                                                                  self.getPropertyData(),
-                                                                  colorbrewer[self._colorBrewerName]);
- 					              feature.map_mouse_over = true;
- 					              console.log(feature);
- 					         });
-					    layer.on("mouseout", function (e) {
-						       feature.map_mouse_over = false;
-                                                // TODO: Move this somewhere else
-						       hoverTract.select(null);
-					    });
-
-
+					$.each(geojsonLayer._layers,function(idx,layer){
+						var feature = layer.feature;
+						feature.highlighted = false;
+						hoverTract.watchForValue(feature.id,
+							function() {
+								feature.highlighted = true;
+								layer.setStyle(self._styleFunction(feature));
+							}, function() {
+								feature.highlighted = false;
+								layer.setStyle(self._styleFunction(feature));
+							});
+						layer.on("mouseover click", function (e) {
+							if (!hoverTract.contains(feature.id)) {
+								hoverTract.clear();
+								hoverTract.select(feature.id,
+									feature,
+									self.getPropertyData(),
+									colorbrewer[self._colorBrewerName]);
+							}
+						});
+						layer.on("mouseout", function (e) {
+							hoverTract.deselect(feature.id);
+						});
 					});
 
 					if (this._layers_id[add[i]]) {
@@ -318,7 +316,7 @@ define([
 
 			},
 
-			_styleFunction : function(feature,highlight) {
+			_styleFunction : function(feature) {
 
 				 if (this._itemStyle){
 					return this._itemStyle(feature);
@@ -331,8 +329,8 @@ define([
 					 var val = parseFloat(feature.properties[this._currentProperty]);
 
 					 if (val) {
-						if ((typeof(highlight)!=="undefined") || feature.map_mouse_over==true) {
-					 		return {"fillColor": this._getColor(prop.serie, val) , "color" : "#404040" , "weight": 4 , "opacity" : 1.0,  "fillOpacity": 0.6};
+						if (feature.highlighted) {
+							return {"fillColor": this._getColor(prop.serie, val) , "color" : "#404040" , "weight": 4 , "opacity" : 1.0,  "fillOpacity": 0.6};
 						} else {
 							return {"fillColor": this._getColor(prop.serie,val) ,  "weight": 0 , "opacity" : 0.0,  "fillOpacity": 0.6};
 						}
diff --git a/src/scripts/iwindow.js b/src/scripts/iwindow.js
index 80c4f0a..ac3dfd4 100644
--- a/src/scripts/iwindow.js
+++ b/src/scripts/iwindow.js
@@ -99,11 +99,14 @@ define(['jquery', 'underscore', "hoverTract", "variables", "colors"], function($
                     currentVar = varname;
                     render();
                 });
-            hoverTract.watch(function(_, _, feature, prop, colors) {
-                //console.log(feature);
-                currentFeature = feature;
-                currentProp = prop;
-                currentColors = colors;
+
+            // Watch for changes, ignoring any selected
+            // tracts after the first.
+            hoverTract.watch(function(tracts) {
+                var tract = _.first(tracts) || {};
+                currentFeature = tract[0];
+                currentProp = tract[1];
+                currentColors = tract[2];
                 render();
             });
 	}
diff --git a/src/scripts/subSelect.js b/src/scripts/subSelect.js
index 2df79a1..59f151b 100644
--- a/src/scripts/subSelect.js
+++ b/src/scripts/subSelect.js
@@ -8,7 +8,9 @@ define(["underscore"], function(_) {
 
                 // Callbacks that run whenever the selection changes.
                 callbacks: [],
-                selected: null
+
+                // Selected values, stored as key/value pairs.
+                selected: {}
             };
 
             return {
@@ -37,30 +39,77 @@ define(["underscore"], function(_) {
                     pub.callbacks.push(handler);
                 },
 
-                // Sets the currently selected value to v and informs
-                // all subscribers.
-                select: function(v) {
-                    var old = pub.selected,
-                        args = _.rest(arguments);
+                /**
+                 *   Publish updates to all subscribers, and (optionally)
+                 *   all watchers on a given key.
+                 *
+                 *   @param {array|string} keys Key/keys for which to
+                 *   update subscribers.
+                 */
+                publish: function(keys) {
+                    keys = keys || [];
+                    keys = _.isArray(keys) ? keys : [keys];
 
-                    if (old) {
-                        _.each(_.pluck(pub.subscribers[old], 1), function(f) {
-                            if (f) f.apply(this, args);
-                        });
-                    }
+                    var selected = _.values(pub.selected);
 
-                    if (v) {
-                        _.each(_.pluck(pub.subscribers[v], 0), function(f) {
-                            if (f) f.apply(this, args);
-                        });
-                    }
+                    var self = this;
+                    _.each(keys, function (key) {
+                        _.chain(pub.subscribers[key])
+                            .pluck(self.contains(key) ? 0 : 1)
+                            .each(function (f) {
+                                if (f) f.apply(this);
+                            });
+                    });
 
                     _.each(pub.callbacks, function(f) {
-                        if (f) f.apply(this, [v, old].concat(args));
+                        if (f) f.apply(this, [selected]);
                     });
+                },
 
-                    pub.selected = v;
-                    return old;
+                /**
+                 *   Adds v to the currently selected set and informs
+                 *   all subscribers.
+                 *
+                 *  @param {string} v Key/ID of selection.
+                 *  @param {Object...} args Arguments associated with the selection.
+                 */
+                select: function(v) {
+                    var args = _.rest(arguments);
+                    pub.selected[v] = args;
+                    this.publish(v);
+                    return _.values(pub.selected);
+                },
+
+                /**
+                 *   Removes v from the currently selected set and
+                 *   informs all subscribers.
+                 *
+                 *   @param {string} v Key/ID of selection.
+                 *   @param {Object...} args Arguments associated with the selection.
+                 */
+                deselect: function(v) {
+                    pub.selected = _.omit(pub.selected, v.toString());
+                    this.publish(v);
+                    return _.values(pub.selected);
+                },
+
+                /**
+                 *   Clear all selections and inform subscribers.
+                 */
+                clear: function() {
+                    var keys = _.keys(pub.selected);
+                    pub.selected = {};
+                    this.publish(keys);
+                    return pub.selected;
+                },
+
+                /**
+                 *   Returns true if the key is selected, else false.
+                 *
+                 *   @param {string} v Key/ID of selection.
+                 */
+                contains: function(v) {
+                    return  !!pub.selected[v];
                 }
             };
         }