There are plenty of natives voting for slavery, and plenty of immigrants voting for freedom, so I don’t think it’s as simple as that.
Yeah, it is as simple as that.
For instance America was founded by a population that was about 99.5% or Protestant, Protestants have only gone democrat 3 times, 1932, 1936, and 1964, and 1964 would not have have happened if the Protestants had won the close, (even stolen) 1960 vote.
If you look at voting, whites vote against the democrats, even white women vote republican.
Without immigration the democrats wouldn’t exist as we know them, that is why JFK devoted so much of his life during the 1950s and early 60s in leading his party to pass the 1965 Immigration Act, and replace the American people with foreign voters.