Science Debate 2008
Originally , the four top candidates for the 2008 election , Hillary Clinton , Barack Obama , Mike Huckabee , and John McCain , were officially invited to discuss science and technology issues at Philadelphia's Franklin Institute on April 18 , 2008 . However , after none of the candidates agreed to participate in the debate , a second invitation was sent , proposing a debate at Portland State University on May 2 , May 9 , or May 16 . 
<triplet> Franklin Institute <subj> Philadelphia <obj> located in the administrative territorial entity