Why? You don't like facts and truth? Believe what you want, but it is quite provable.
From 1868 to 1932, black people voted exclusively Republican. After LBJ created his great vote buying scheme, black people went from being split between the two parties to voting exclusively Democrat. (95% now.)
The big government liberals who like high taxes have always lived in Boston, New York, Washington DC, Chicago, and so forth. Guess where these same liberals live today?
Yes, Liberals live in the North East, and they always have, but back in 1860, the liberals called themselves "Republicans."
Did it happen after George Wallace?
Were the 1960s Democrats segregationists?
Terribly wrong there. A century ago the New England Yankees were penny pinching conservatives. Southerners and Westerners were poorer and were the big spending liberals.
Urban political machines became favorable towards federal spending when it was offered, but virtually all the urban machine politicians were Democrats, and in those days, Republicans could still get elected in Boston, New York, Chicago, and other cities.