I think you just answered what you're wondering about. Why don't people base their beliefs on something solid? How can they, when you admit that Biden will likely change his policies and become more moderate after securing the nomination.
Yes, that's a sound political strategy, but that doesn't make it something that allows voters to base their beliefs on something solid.
For those of us that actually pay attention (and that seems like it includes you and me) when a politician does that, it makes me trust them less. Actually, it would be hard for me to trust any politician less.
