The economic rescue packages enacted during the period spanning the end of the Bush era and the start of the Obama era.
Attitudes to military intervention abroad. When 80s Republican administrations were coddling Saddam Hussain as an ally, liberals were screaming about the injustices in that country and calling for intervention; when conservatives flipped to wanting to oust Saddam Hussain liberals were largely against it - though little had changed for the better internally in Iraq. The flip on Libya when it was the Obama admin working towards the overthrow of Gadaffi, etc. The Republican history of isolationism flipped to a bold militarism. Bush running against nation building/intervention then building a Presidency on it.
The free trade/human rights dichotomy re: China - where the parties swap positions from agitation to accommodation depending on who's in power. Similarly with NAFTA.
I suspect if you don't see policy continuation between administrations in the US, despite the extreme polarization of politics where most R voters will argue against ANYTHING done by a D administration and vice versa, which is exactly the point made, then it may be you seeing what you want to see.
Republicans haven't been isolationist since the 40s.
There is little, if any extreme change in D voters over the last several decades. There is no vice-versa, it's false equivalence nonsense.