title: R xmlParse() Indexing
body: <p>I have data generated from <code>xmlParse()</code>. I am able to obtain a reference to an XMLNode called <code>root</code></p>
  
  <pre><code>&gt; class(root)
  [1] "XMLInternalElementNode" "XMLInternalNode"        "XMLAbstractNode"     
  </code></pre>
  
  <p>When, I do</p>
  
  <pre><code>&gt; root[[2]][[1]]
  &lt;tr class="party-republican race-winner"&gt;&lt;th rowspan="5" class="results-county"&gt;Autauga &lt;span class="precincts-reporting"&gt;100.0% Reporting&lt;/span&gt;&lt;/th&gt;&amp;#13;
                                  &amp;#13;
                                  &lt;th scope="row" class="results-candidate"&gt;M. Romney&lt;/th&gt;&amp;#13;
                                  &lt;td class="results-party"&gt;&lt;abbr title="Republican"&gt;GOP&lt;/abbr&gt;&lt;/td&gt;&amp;#13;
                                  &lt;td class="results-percentage"&gt;72.6%&lt;/td&gt;&amp;#13;
                                  &lt;td class="results-popular"&gt;    17,366&lt;/td&gt;&amp;#13;
                              &lt;/tr&gt; 
  </code></pre>
  
  <p>I try to reference the value in side the tag:</p>
  
  <pre><code>&lt;td class="results-percentage"&gt;
  </code></pre>
  
  <p>However doing <code>root[[1]][[2]][["&lt;td class='results-percentage'&gt;]]</code> returns null</p>
  
  <p>What am I doing wrong that prevents me from accessing the 72.6% value?</p>