The problem of definitions can’t simply be ignored. The Republican Party became the conservative party when investigative journalism largely died with massive media conglomerates took over most of the methods of information distribution. Their reporters blithely call Republicans conservatives because their bosses tell them to. And if you repeat a lie loudly enough, and often enough, people begin to believe it is true. In actual fact, wanting to get rid of the core institutions that have served us for 70 years or more and try radical new forms of governance is NOT conservative. It is the exact opposite.
So it’s true that today, the Democratic Party is the true conservative party, and it is grudgingly nudged ahead from time to time by its progressive wing.
How did it get that way? Republicans gravitated to representing the rich and big business. There’s lots of money in that, and the money was attractive as a way to fight Democrats, who had raw numbers of membership on their side after Hoover presided over the Great Depression.
But the problem is it’s hard to win elections with just part of the top 1% voting for you. So Republicans set their sights on finding voting blocks they could attract with promises of pushing their pet cause.
First, the Neo-Cons left the Democratic Party in the 60s when Democrats befriended the war protesters. Seeing a voting block to grab, the Republican Party welcomed them in. Next, when Lyndon Johnson ordered Federal Troops into Selma Alabama to enforce the Civil Rights act, the Dixiecrats split from the Democratic party. Republicans swallowed the solid South. When Democrats defended abortion rights, the Christian Right moved over to a welcoming Republican Party.
So the liberals in the Republican Party (there would have never been a voting rights act and a civil rights act without Republican votes to overcome the Dixiecrats’ opposition) slowly got purged. Today’s Republican Party became the disgusting sack of s**t it is by eating the detritus of the Democratic Party in hopes of consolidating enough disparate special interest groups to be able to pass laws that benefit multinational corporations and the wealthiest Americans.
Call that a brief and ugly history of the last 80 years in American politics.