With former Governor Carl T.C. Gutierrez declining to challenge his former Lt. Governor and (current) Guam Delegate Madeleine Z. Bordallo for the Democratic nomination, that still leaves Bordallo facing a primary.
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According to Guampdn.com, Karlo Dizon will announce his run for Guam Delegate as a Democrat on Monday, May 14. Dizon is a former campaign member for then Senator Barack Obama's 2008 Presidential Campaign on Guam.
As of this time, the race for the Democratic primary is still Bordallo's to lose, judging by her overwhelming victory in her last contested primary against Jonathan Blas Diaz and the support of Governor Gutierrez.