Recently, (over the past 30 years or so) there has been a great polarization. The terms “liberal” and “conservative” were not associated directly with the terms “Democrat” or “Republican”. There were even politicians who might have been called “Liberal Republicans” or “Conservative Democrats”.
The Democratic Party traditionally stands for a regulated economy, using government intervention and regulation in the economy. These interventions (such as the introduction of social programs, support for labor unions, moves toward universal health care and equal opportunity, consumer protection, and environmental protection), have been at the core of most of the party’s platform over the last seventy-plus years or so.
The Republican party traditionally stands for a free-market economy, free enterprise, business, a strong national defense, deregulation, restrictions on labor unions, social-conservative policies, and traditional values.