I have changed the site to use Razor.

What's the trick for referencing my taxonomy tag?

@using DotNetNuke.Web.DDRMenu;
@{var root = Model.Source.root;}

@helper RenderNodes(IList<MenuNode> nodes) {
 if (nodes.Count > 0) {
  <ul class="navigation_horizontal">
    @foreach (var node in nodes) { 
     <li>
      @if (node.Enabled) {
       if(node.First){
        <a href="@node.Url">@node.Text</a>
      }else{
        <a href="@node.Url">@node.Text</a>
      }
     }
     @RenderNodes(node.Children)
        </li>
   }
     </ul>
 }
}
@RenderNodes(root.Children)