The refrain essentially is that you must vote for the candidate we say is most likely to win and if you don't, then you're helping the next runner up.

I believe that if we no longer reported polling results and had election results reported at the same time, then the problem I describe above would be significantly reduced.

The fact that primaries are not held at the same time leads the results of earlier primaries influencing the results of later ones. The fact that election results from the eastern part of the country are reported while the western part is still voting influences the results.

We desperately need a voting system that allows you to express your preferences honestly, and ideally across all candidates, without hurting the outcome. By far, score voting systems are the best at that. Of those, I recommend STAR voting (Score Then Automatic Runoff), because it has some actual momentum[1] (it also has some theoretical advantages, but both it and vanilla score voting, and even Ranked Choice with a Borda count, are such a massive improvement over the status quo that it doesn't matter which we pick).

[1]: https://www.starvoting.us/ -- no affiliation, just convinced by the research (edit: which you can mostly find linked from https://www.equal.vote/)

It's also unlikely to ever happen, because the only ones with the power to do it are the ones that would be displaced.