For the same reason they have twisted the word “liberal” from its original, honorable meaning — to claim they are something they are not.
(Note to those who may be historically deficient — a liberal from the 18th century holds many of the same positions as a conservative today, and an 18th-century conservative would feel comfortable in the Democrat Party today. Also, the Republican Party was formed around a radical agenda — abolition of slavery, and promotion of individual liberties. They were called liberals in the 19th century.)
Look at how they rule the city states hey control Chicago is a one party hereditary monarchy. Their’s is a patronage system, not a democracy or meritocracy, as they claim. Socialists took over the traditional Democrat party. As Pat Cadell put it during the 2000 election recount. “My god, the party of my grandfather has been taken over by gangters.”