Wisconsin Gov. Scott Walker is reflected by glass before speaking at a leadership summit in Nashua, New Hampshire, on April 18, 2015. Walker, who rose to national fame by taking on unions in one of the most blue-collar states, &amp;lt;a href=&amp;quot;http://www.cnn.com/2015/07/13/politics/scott-walker-2016-presidential-announcement/&amp;quot; target=&amp;quot;_blank&amp;quot;&amp;gt;officially became a presidential candidate three months later.&amp;lt;/a&amp;gt;