TL;DR: the "significant political event" was a drastic lowering of reported crime rate since he took office
The Philippine National Police (PNP) said the crime rate in the country dipped 31 percent in July, compared to the same period last year.
During the second day of the Senate's hearing on alleged extrajudicial killings Tuesday, PNP Chief Ronald Dela Rosa reported "a very significant decrease" in rape incidents. Dela Rosa said there is also a "downward trend" in the so-called "focus crimes," including murder, homicide, robbery, theft, "carnaping" (car theft), "motornapping" (motor theft), and physical injuries.
A total of 11,800 crimes were reported in July 2016, lower than the 17,105 crimes listed in July 2015.
Data from the Philippine Drug Enforcement Agency (PDEA) show there are 11,321 out of 30,715 barangays (districts) nationwide considered "drug-affected."
So... for a Philippine citizen worried that their loved one will be a victim, let's weigh their concerns:
On one hand, they could be a victim of a crime (140K index crimes a year as per ABC) - meaning, in 8 months since the election, that's ~100K index crimes; and 13% drop means 13K less crimes - which the populace attributes to Duterte (regardless of whether that's correct). And at least 2000 of them were murders that didn't involve war on drugs (that was 2015 stats).
On the other hand, they could be a victim of a War on Drugs - there are 2,200 as you noted; and if we assume that as much as 25% of those were innocent (unlikely but let's be generous and assume hitmen hired by police killed drug dealers only 50% of time), that means 500 innocent victims.
So, an average citizen bases their favorable view of him on the fact that unless they are involved with the drug trade, they are 13x times less likely to be a victim of a rogue crime that's part of war drugs; than a non-victim of a crime that war on drugs is percieved to have prevented.