Liberalism is a conservative ideology. Conservative meaning maintaining the status quo, which liberalism does for economic, foreign, and social policy

Edit: down vote all you want but it is true. The last time liberalism was progressive was when the divine right of kings was law of the land.

Political ideologies can broadly be categorized as reactionary (supports a real or perceived status quo ante), conservative (supports maintenance of status quo), and progressive (supports developing new systems). There are the axes of social views, economic views, etc that we apply these to. The major political parties in the US are centered around variants of liberalism, the ideology of individual rights and private property, which is focused on the status quo of imperialism, discriminatory social hierarchies, and capitalism. There are those who think these systems don't go far enough in their repression, especially but not exclusively within the GOP. They are reactionaries. Progressive ideologies only find any foothold on the very fringes of the DNC, but they are fighting against the policies and institutions of the party itself, not really influencing it fundamentally.