Philippine election: what challenges will Bongbong Marcos or Leni Robredo face in the militant hotbed of Mindanao?

• Whoever wins the May 9 presidential election will have to deal with the security and political complexities in Mindanao, analysts say, including seeing through a peace process
• Frontrunner Marcos Jnr doesn’t have a clear policy for the region but has the clout to enact policies, while closest rival Leni Robredo has expressed support for regional autonomy