A Philippine senator who is an ally of Vice-President Sara Duterte-Carpio was arrested on Monday on a plunder charge, hours before the Senate begins a high-stakes impeachment trial that could determine Duterte’s political future.Senator Rodante Marcoleta was due to sit as a senator-judge on Monday at the impeachment trial against Duterte-Carpio. If convicted by a two-thirds majority in the 24-member Senate, Duterte-Carpio could be barred from running in the 2028 elections, where she remains...