Agreed, + Bandwagon Effect, Tactical Voting, plus other effects?
I haven't come across a term that covers what we're talking about in full scope(?)(hence my clumsy tug of war metaphor), but that's probably because I am peripheral to game theory / not in the psychology space
(We have lots of terms for the emergent effects - Overton window, Political Polarization etc. - But possibly not for the overall phenomena of why polarization occurs?)