They and their parties have realised that you can get away with more and more. If you can rile up one extreme to offset losing the centre, that's a win for them

They and their parties have realised that you can get away with more and more. If you can rile up one extreme to offset losing the centre, that's a win for them as they hold power for longer. The candidates are largely dispensable and compensated in one way or another for taking risks. I'd guess that the more critical an issue feels to your adherents, the more you can get away with.