In the polarized climate that exists in today's political world, it is astounding to remember that the Republican Party began as a political party dedicated to liberalism.
Republican President Abraham Lincoln, the first Republican Party president, took leadership in freeing the slaves. He advocated for equality of all people in the United States. He was a leader in introducing many liberal thoughts into American politics.
The Republican Party remained a liberal-based party for many years. Teddy Roosevelt offered many liberal ideas, including health care reform, establishment of national parks, and advocating for what the federal government could to for Americans. He saw an activist federal government in America.
Following the Civil War and Lincoln's freeing the slaves, Reconstruction began in the South. It was terribly administered. But African American men were finally granted the right to vote and have equal rights. In reaction to the liberal programs of the Republican Party, white Southerners banded together in unison and became staunch members of the Democratic Party. A former Confederate calvary leader, Nathan Bedford Forest, founded the Ku Klux Klan and most of the members of the KKK were solidly behind the Democrats and fought hard against civil rights. Republicans fought to move equality forward in the South and this continued to alienate whites, thus the white southerners were leaders in the Democratic Party. Democrats in the South passed Jim Crow laws to keep blacks from having equal rights.
How could this have changed so dramatically for the Republican Party to become so anti-liberal? By far the most important reason was when Democrats in Congress and the White House began to enforce equal rights in the South. Political leaders in the South like Strom Thurmond, Jesse Helms, and George Wallace began to criticize the Democratic Party and whites began to leave the Democrats. In fact, Strom Thurmond left the Democratic Party and ran for president as a Dixiecrat. Later Thurmond, a devoted bigot, switched to the Republican Party and became a GOP member of the U.S. Senate. Wallace also left the Democrats and ran for president as an independent. In brief: bigotry caused the political parties to switch, to flip-flop in the 20th century. Bigotry and prejudice were the overwhelming drive that caused all of Southern politics to become not only Republican but anti-black. Suddenly KKK members were all Republican. How much has this driven what the Republicans stand for today and their focus on keeping the President of the United States from passing his legislation agenda? Easy to answer....
Look at the color of skin of the current resident of the White House.