Simplify the following text for a Grade 9 native English-speaking person.
Original: On September 7 , 2007 , PeÃ a announced that he would endorse Senator Barack Obama in the 2008 presidential election , and also serve as Obama 's National Campaign Co-chair .
Simplified: On September 7 , 2007 , PeÃ a announced that he would support Sen. Barack Obama in the 2008 presidential election , and also serve as Obama 's National Campaign Co-chair .