@Ninja EDIT: I wanted to shorten my answer to the essential point.
What i criticise about your view is that you do not put enough value onto the longterm consequences of actions of politicians. You think that a party should listen to the majority opinion while putting values on a backseat because winning is the highest virtue. But even if it was believable that this would offer more short term wins (and I dont think it does), it surely cannot not accomplish a better or at least equally good world, which is the ultimate goal of politics. And that is why it falls short.
Trust is a hard currency. Both trust into indiciduals and trust into the political system itself. Every time a politician promises something and flip flops, trust is eroded. The same goes for every time obvious party games or lobbyism (like Pelosis insider trading) is done without consequences or the state fails its constituents in other ways.
What people need is leadership that they can trust and that is what they will vote for. Centrist politicians are unable to keep that trust up, because they increasingly pomise things they have no intention of upholding and build their promises around fleeting polls rather than a fundament of values.
There are two mainmechanisms that can make you gain or lose trust with a voter:
1) You are the only one who seems to understand an issue they have and you are willing to fight for it. On the flip side, you lose trust into someone who seems to handwave an important issue you have away. If almost all politicians do that, a voter loses trust in politics (for example when he struggles to get by and the government says economy is great and they did a good job).
2) You are willing to fight for an opinion the voter shares even if you get a lot of flack for it. They know they can trust you because you were in solidarity to the voter when it meant you would get hurt by it. On the flip side, if you flop flop on issues because of party line or occasion, you lose trust.
Trump did both of these things a lot (so did AOC, which is why the voters you mentioned liked both of them. They favor trust). Trump definitely also flip flopped a lot and lied through his teeth, but nobody can deny trump did not cave to pressure and gave validity to concerns that nobody else seemed to give validity too. He did it in an evil, dishonest way, but he did. A lot of democratic leaning voters did not feel like Harris had some of their most important issues adressed, and if she did, they didnt really believe she meant it.
The reason trust is such a hard currency is that you can build an actual longlasting political force on it with voters that actually like or at least accept what you do and who trust the political system. But today, increasingly, it seems like nobody in politics has any values anymore. Newsom can turn on the homeless, Kamala can turn on the greendeal and champion more gas drilling and of course republicans do not even know what truth is anymore.
If you bank on short term wins via strategic positioning, that means you will have to break that trust time after time, because you are not telling the full truth and you fight for contradictions, misguided compromises or things you simply have no intention to actually do.