The alleged U.S. "party switch" claim made by liberals ,and progressives over decades is a political hoax and conspiracy theory that attempts to smear the Republican Party. The narrative, which has been crafted with the help of Communists (who infiltrated the Democrat Party over the decades and who are known to lie, deceive, and engage in historical revisionism for the sake of being contrarian), typically assumes that the Democrat and Republican parties "switched sides" during the 1960s, where the Republican Party somehow became the party of "racists" and the Democrats suddenly becoming the "champions of civil rights." Many reputable historians and political scientists such as Carol Swain (see this video) and political commentators such as Bob Parks strongly agree that the parties did not switch sides, as the Democrats only switched strategies with Communist help.
While many modern leftists will note the liberal policies promoted by the Republican establishment for a while during the 1900s that dissipated in the 1960s to promote their myth, it's important to note the conservative roots of the early foundations of the Republican Party, as mentioned below. Leftists also falsely characterize President Dwight D. Eisenhower as a liberal Republican when he tended to favor conservative policies.
Some leftists including the extremist hate group Occupy Democrats imply that the current Republican Party models past racist Democrats in using racially charged baiting to maintain their voter base. This is false, as patriotic conservative Republicans since the party's foundation have consistently advocated for the same pro-civil rights, pro-human rights, pro-free market, pro-business, pro-tariff, and nationalist principles as well as emphasizing on individual responsibility. Furthermore, these liberal charges ignore the fact that the modern-day Democratic Party treats black voters in the same respect it regarded poor Southern whites in the past.