President Barack Obama has endorsed Senator Brian Schatz in Hawaii's U.S. Senate election.  A statement was released from the Senator's campaign office Monday. The endorsement could prove to be key for Schatz, who chaired President Obama's 2008 campaign efforts in Hawaii, as he enters a challenging race against fellow Democrat and U.S. Representative Colleen Hanabusa. In the endorsement statement, President Obama says he has worked with Senator Schatz on the issues that matter to Hawaii, and his deep commitment to the people of Hawaii and effective leadership are why Obama believes he should return to the Senate.