The Democratic Party has changed significantly over the past century with many of its members moving to other parties between the 1950s and today. Changes in political issues and political candidates motivated these transformations. While the Democratic Party of the 1950s is different from today, some of its issue positions on economic and social policy issues remain the same.

Southern Democrats

In the 1950s, most Southern white voters were members of the Democratic Party, but today this is far from the case. In the 1950s, Southern white voters were considered part of the "Solid South," a voting block that almost always went to the Democratic Party. Throughout the 1960s, however, the issue of racial desegregation gradually drew many Southern white voters away from the Democrats. When the Civil Rights Act of 1964 was signed, for example, 115 of the former Confederate states' 128 members of Congress were Democrats. That has reversed today; in 2010, only 24 of their 155 members were Democrats.

Black Voters

Over the past century, black voters moved first into the Democratic Party under Franklin Roosevelt, and then again under Lyndon Johnson, thanks to civil rights issues. While a majority of the black vote went to Democratic candidates in the 1950s -- in 1956 only 39 percent of blacks voted Republican -- their majorities have increased considerably since. In 2012, for example, 93 percent of blacks voted for the Democratic candidate Barack Obama, and only 6 percent voted for Republican candidate Romney.

Reagan Democrats

Especially under the presidency of Ronald Reagan, so-called "Reagan Democrats" moved from the Democratic Party to the Republicans. These voters were motivated by changes in social issues, including topics like abortion, religion and same-sex marriage. Over the course of the past half century, these voters, often working class and lacking college degrees, were attracted to the Republican Party's calls for a smaller government, and they thus left the Democratic Party in large numbers between the 1950s and today.

The 1950s and Today

On economic policy issues, for example, the Democratic Party remains committed to supporting government intervention on issues like poverty and education. This is consistent across time, from FDR's New Deal in the 1940s and Harry Truman's Fair Deal to Lyndon Johnson's 1960s War on Poverty and Barack Obama's Affordable Care Act today.