In America elections are fought on turnout. The Democrats in their infinite wisdom thought swinging right would allow them to win on swing voters while losing massively on turnout. To top it off one of the few swing demographics is unions (who are often conservative and, obviously, pro-union) and Schumer lead the charge in abandoning them for the suburban progressive vote a few decades back, and then they threw away the progressive vote by going in hard for Israel.

In Australia, swing voters genuinely do decide elections. The most effective leaders in Australia are radical pragmatists. Furthermore Labor never really abandoned the unions (despite some hickups). If the Liberals get their way with optional preferential voting then Labor may be stuck between a rock and a hard place and we'll end up like Japan with a century of uninterrupted Liberal government though.