Well the first issue here is that your characterisation of both the left and the right is off from the actual values they represent. For instance the Republican party is actually surprisingly progressive when it comes to the gays (One of Trump and Vance’s biggest funders is Peter Theil a gay man) see Charlie Kirk.

The democratic party has only recently changed its position on gay marriage open borders etc. See Joe Biden and Hillary Clinton.

Historically many black people have voted Democrat because that is just what they have done and Obama played into this and secured this trend for a while longer.

Black people in america have always been quite homophobic as a demographic. This is why /pol made the Swastika black and brown when they redesigned the pride flag. They thought it would be funny to associate black people with gay people on the new flag.

Given all this people have opinions for various things and they value each of these things differently. They will thus logically vote for whoever best aligned with what they believe putting more weight towards those that support things they believe strongly. Their is of course some tribalism factor of I’ve always voted x thus I will continue voting x but logic will supersede this for a majority of people given their tribe becomes extreme enough.

This is why free speech in the philosophical sense is so important. It allows people to discuss their ideas and allows the best one to win in the marketplace of ideas.