@jaroonn is correct about the parties switching, starting in the 1960's thru the 80's. If @raphjd had ever taken a political science class in a university, then he'd know that. But, as we all know, @raphjd thinks reading books makes you dumber.
But, for context...
The Great Switch: How the Republican & Democratic Parties Flipped Ideologies
"In 1964, Democratic president Lyndon B. Johnson signed the Civil Rights Act into law. In the 1964 election, Republican candidate Barry Goldwater publicly opposed the new law, arguing that it expanded the power of the federal government to a dangerous level.
It was this argument that led to a final, decisive switch. Black voters, who had historically been loyal to the Republican Party because of the 1866 Civil Rights Act, had already been switching to the Democratic Party.
However, upon hearing Goldwater’s argument against the 1964 Civil Rights Act, the majority of Black voters left the Republican Party in favor of the Democrats. They saw the Democratic Party as advocates for equality and justice, while the Republicans were too concerned with keeping the status quo in America.
As the 60s and 70s continued, Democrats sought reform in other places, such as abortion and school prayer. White southern Democrats began to resent how much the Democratic Party was intervening into the rights of the people.
By the 1980s, white southern Democrats had become Republicans, and the majority of the south was now Republican. The Republican Party now is solidly conservative while the Democratic Party is the liberal one."