What does One Nation's historic win in WA mean for our political landscape?

WA Labor has been defeated in a state by-election that's been branded a "litmus test" for One Nation in the west.The ABC's chief election and data analyst Casey Briggs called the seat of Secret Harbour in Perth's south for One Nation's Luke Herdegen a little over four hours after votes began to be counted.So what does it mean for our political landscape across the country?