Because it creates chaos and conflict within the Democrat Party which does not have a big tent.
The party’s radical hard-core are fervent socialists but they can’t get a dog elected without the Reagan Democrats, those conservative, bible-believing, gun-toting, middle-class hard working group (not solely white) who have values that include national defense, love of country, and love for God.
Neither Hillary nor Obama, both far-far-left wing Dems, can bring those conservative Democrats to the polls. And Rush Limbaugh knows that and now you know too.
Hillary, with the help of the MSM and (sadly) Rush, has positioned herself as the candidte for the “Reagan Democrats.”